THE SECRET OF WILDCAT SWAMP

An invitation from Cap Bailey, science teacher at Bayport High, to accompany him out West to Wildcat Swamp on an archaeological expedition triggers off a series of dangerous events for Frank and Toe Hardy.

Just before they leave, a ruthless criminal breaks out of prison. Their famous detective father, who is tracking down a gang of freight-train robbers, suspects the escapee is part of the gang. Investigation leads him to believe that the robbers might be hiding out in Wildcat Swamp!

On their way West the boys and Cap have a near-fatal accident in a private plane which has been sabotaged. When they start digging for fossils, a giant boulder comes hurtling straight toward them as if guided by an invisible hand. Though warned to leave the area, Frank, Joe, and Cap doggedly remain until they have caught the cunning ex-convicts they are up against in this swift-paced adventure.

âNice cave mates you pick for yourself!â
Frank remarked

Copyright Â© 1997,1969, 1952, by Simon & Schuster, Inc.

All rights reserved. Published by Grosset & Dunlap, Inc., a member of The Putnam & Grosset
Group, New York. Published simultaneously in Canada. S.A.
THE HARDY BOYSÂ® is a registered trademark of Simon & Schuster, Inc.
GROSSET & DUNLAP is a trademark of Grosset & Dunlap, Inc.
Library of Congress Catalog Card Number: 69-14267

eISBN : 978-1-101-07645-3

2008 Printing

http://us.penguingroup.com

CHAPTER I

Prison Break

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âIF SOMEBODY doesnât toss a mystery our way, fellows, we may actually be swimming in this pool one of these days.â

Frank and Joe Hardy stopped digging and leaned on their shovels. The boys grinned as they studied the perspiring, chubby face of Chet Morton.

âShall we tell him, Joe?â Frank asked with an exaggerated lift of his eyebrows.

âTell me what?â Chet demanded. âAw, listen, fellows! Long before school closed for the summer you promised me youâd come out here to the farm and help me clean out this bog.â

Eighteen-year-old Frank Hardy, with a wink at his brother, who was only a year younger, gazed thoughtfully at their best friend.

âWell, arenât we helping?â he said. âBut how would you like to help us catch a couple of train robbers, Chet?â

âNo kidding!â Joe added. âLast night Dad was talking about one of his cases, and said maybe we could help him.â

The brothers, sons of Fenton Hardy, an internationally known private detective, frequently assisted their father. Their first mystery had been The Tower Treasure, and not long ago they had solved The Wailing Siren Mystery. Chet Morton had often shared their exciting adventures, but he preferred the enjoyment of a good meal to such strenuous activity.

âTr-train robbers! Iâd rather dig,â Chet retorted.

He sent his long-handled shovel deep into the mire. Then, with a heave, he hoisted a load of muck and shale to the high ground behind him.

âSay, look at that shale you just tossed up!â Joe exclaimed. âIt cracked open, and there are funny-looking marks inside it!â

Curious, Frank picked up a piece of the shale and inspected it more closely.

âLooks like indentations from old clamshells, doesnât it?â he remarked.

âOh, you find all sorts of queer marks on rocks and things which have been under water,â Chet answered. âThatâs nothing at all. Throw the silly thing away and letâs get on with this job!â

Just then a voice sounded behind him. âWait! Donât throw that away. Itâs valuable!â

Turning, the three boys discovered Thomas âCapâ Bailey, popular track coach and science teacher at Bayport High, standing on the rim of the excavation. He was not much older than his students, who held the twenty-five-year-old instructor in high regard.

âWait! Donât throw that away!â

âThatâs a brachiopod!â he exclaimed, examining the piece of shale.

âA w-who?â Chet stuttered.

âItâs a valuable fossilâmaybe millions of years old,â Cap said with a smile. âThey turn up every now and then in different corners of the world, and scientists use them to trace the development of man and animals through the ages.â

Crouching down, he showed them what a perfect specimen the brachiopod was.

âYou ought to take this to the Bayport Museum, Chet. I doubt that thereâs one like it in their collection.â

Then Cap spoke directly to the Hardys. âHow would you fellows like to combine some detective work with fossils?â

âI knew it!â Chet moaned. âHere goes our pool. Itâll never be finished now.â

Frank and Joe eagerly questioned the science teacher for more details.

âA week before school closed,â he said, âI received a letter from an aunt who lives out West. Her husband, Alexander Bailey, died recently, just when he was on the verge of an important discovery.â

âWas he a scientist, too?â Joe inquired.

âYes, a geologist. It seems that about a year ago he uncovered part of what appeared to be the giant fossil of a prehistoric camel that once roamed the western United States. Soon after his discovery, one of those terrific western storms hit the spot and completely obliterated all of his work. Then he was taken ill and never recovered.â

âToo bad,â Frank murmured.

Chet asked how Capâs aunt expected him to find the camel since all trace of his uncleâs work was lost in the storm.

âI havenât told you all the story,â Cap replied. âBefore he died, my uncle scratched out a rough map of the section, with the location of his original discovery indicated on it. Itâs a place called Wildcat Swamp.â

That was all Chet needed. âWildcats!â he exclaimed. âTheyâre dangerous!â

âProbably itâs called Wildcat Swamp,â Cap Bailey went on, âbecause not far from the site of his discovery he had found a sign reading: âHere lie the bodies of twenty wildcat.â â

âThatâs strange,â Joe remarked. âTheir killer must have been a mighty hunter.â

Bailey nodded, âI guess anyone going into the area would have to keep his eyes open. And, incidentally, Iâve already found out there is some danger to even starting for the spot.â

âWhat do you mean?â the boys chorused.

âWell, after school closed I started for Wildcat Swamp alone, in my car. Any number of people must have heard me talking about what I intended to do. I hadnât driven far when I was held up by two masked men and all my money was stolen. I was told to go back home and stay there.â

âYou think they meant to discourage you from going after the fossil?â Frank asked.

âOf course Iâm not positive, because they didnât mention the fossil, and didnât take the map. That might have been because another car came along and scared them away. But they seemed to know who I was, and mentioned that it would be healthier for me in the East than out West.â

âIt does sound as if they wanted you to give up that trip,â Joe commented. âBut why? They sound more like thugs than scientists.â

Cap Bailey nodded soberly. âThe reason I came out to see you Hardys is this: How would you like to make the trip with me? I think you could be a big help. What do you say?â

âIt sounds wonderful to me,â shouted impulsive Joe. âHow soon do we leave?â

Frank was just as enthusiastic as his brother, but more realistic in his approach.

âThree of us together should certainly be able to handle more trouble than one man alone, but first weâll have to get Dadâs and Motherâs okay.â

As it turned out, that was no problem at all. When they reached home, their quiet, pretty mother said she would leave the decision to their father. After the situation had been explained to him that evening, the tall, well-built detective said:

âI think such a trip would be a good experience for you boys, and besides, it might even work in with the case I asked you to help on.â

âYou mean the train robbers? How?â Frank asked.

âI had my operative Sam Radley tailing a fellow named Gerald Flint after he was released from Delmore Prison. Once Sam overheard Flint use a phrase that sounded like âtwenty wildcatâ in such a way that heâs sure it has some special significance. And now Flint has disappeared.â

âWow!â Joe cried out. âYou donât mean heâs in Wildcat Swamp?â

âI wouldnât go that far,â his father answered. âBut a good detective never misses a clue. If you boys can find out more about the âtwenty wildcat,â it may help me.â

Cap Bailey was pleased to hear that Frank and Joe could go with him.

âIâll give you a couple of days to pack up,â he told them.

Next morning Frank and Joe went to see Warden Duckworth at Delmore Prison. Their father had suggested that perhaps they could find out something about Flintâs associates in jail. The officer was a friend of Mr. Hardy and he gladly spent some time telling the boys about Gerald Flint, an old-timer with a long record. Flint was described as a tall, loudmouthed man, who could be soft-spoken and persuasive when he wanted to be.

âHereâs his picture,â the warden said, and handed them a photograph.

âHis best friends at our prison,â the warden went on, âwere Willie the Penman and Jesse Turk. Willieâs a short, wiry fellow with a high-pitched voice, and one of the most cunning forgers in the country. He was released at the same time as Flint.â

âWhat about the other fellowâTurk?â

âJesse is still here. Heâs a mountain of a manâa former locomotive engineer, and an expert electrician, but not popular. He has a mean look about himâalways frowning at something.â

Frank and Joe were just bidding the warden good-by when they heard a clanging, followed by the deafening roar of a siren.

âThereâs been a break!â Duckworth shouted.

Seconds later, the ringing of the telephone added to the din. Duckworth grabbed the phone. Frank and Joe could hear excited chatter on the other end of the line. The warden turned to the boys, his eyes wide.

âItâs Turkâheâs escaped!â

CHAPTER II

Escape by Train

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HIS face grim, Warden Duckworth ordered his car, then dashed from the office.

âCome on, Frank!â Joe urged, starting down the long, low-ceilinged corridor after the warden.

âI wonder how Turk got out!â Frank cried.

Reaching the outer prison yard, they saw guards everywhere, on the alert with rifles in case more of the prisoners should try to make a break.

âI was told,â Duckworth said to the man at the gate, âthat Turk may have escaped by jumping into a butcherâs truck as it left the prison. Did you see which way it headed?â

âYes, sir. North on Route 403. It was a National Meat truck.â

Three emergency trucks came roaring up, followed by the wardenâs car. As the Hardys climbed in, Duckworth advised them to remain at the prison, but they assured him that they would keep out of harmâs way.

At his direction, the trucks split up to comb the countryside. Other armed guards tramped on foot in search of the fugitive, while the motor crews toured the nearby roads.

âFollow 403,â Duckworth told his driver.

The road passed through a wooded section, and the tires of the wardenâs car squealed as it took the curves at almost full speed.

âDo you think the truck driver planned this with Turk?â Frank asked.

âIâm not sure,â the warden replied. âUsually an escape involves more than one prisoner. Iâd be more inclined to thinkââ

âLook!â Joe cried. âThereâs a delivery truckâItâs a National Meat truck!â

âYou boys stay below windshield level,â Duckworth ordered. âIâm going to force him to stop.â

With a burst of speed they raced past the truck, sounding the siren. The driver slowed and came to a stop.

Warden Duckworth jumped out, gun in hand.

When the driver saw the gun, his jaw fell. âWhatâs the big idea?â he shouted.

âYou may be carrying an escaped prisoner!â

The driver went white as the warden approached the rear doors of his truck and flung them open.

âIf Turk was ever in here, heâs gone now,â Duckworth said disappointedly. âIâll radio the other men.â

Frank and Joe got out and spoke to the driver. âDo you mind if we have a look inside your truck?â

âGo ahead.â

Climbing into the cool interior, the boys began examining it carefully for clues.

âHereâs something!â cried Frank as he picked up a small wooden box. âIt looks like a homemade radio.â

It proved to be a miniature receiving set, so small that it fit snugly in the palm of Frankâs hand. As he turned a knob, the gadget began to sputter.

âRepeating, Turk,â it announced. âFreight delayed. Hook 138576 at three Rock Spring.â

The voice broke off.

âThat was Flintâs voice,â said the warden, who had just jumped into the truck.

âBut what did all the gibberish mean?â queried Joe. âWas Flint in on Turkâs escape?â

âMight have been,â Duckworth retorted tersely. âTurk worked in the electricianâs shop in the prison. He may have rigged up this communications system as part of a planned break.â

âSo when Flint and Willie the Penman got out they could tip him off on how to get away,â Joe suggested.

â âFreight delayed. Hook 138576 at three Rock Spring,â â Frank repeated. âSounds as if a railroad freight may be part of the plan. You said Turk was a locomotive engineer at one time, didnât you?â

âThatâs right!â

âThree Rock Spring might mean time and place. Itâs almost three oâclock nowâand Rock Spring isnât far from here!â

âLetâs get moving. Rock Spring in a big hurry!â Duckworth shouted to his police driver, and they piled into the car. One of the wardenâs men stayed behind to query the truck driver further.

âThereâs a water tower on the line at Rock Spring,â Joe recalled. âBut the road doesnât go in that far, Warden.â

âWeâll have to make the last half mile on foot.â

Reaching the end of the bumpy road, they all jumped out of the car and headed for the rail line. Frank and Joe, still in good condition from track work during the spring, soon outdistanced the others. But before they reached the right-of-way they could hear the rumble of a freight train.

âMaybe weâre too late,â Frank said, puffing. âHey! Here comes a car numbered 138576! Iâll bet thatâs what the message meant!â

Before Joe could answer, the car had passed them. Suddenly the sliding door of the boxcar opened. Then, as car 138576 moved still farther ahead of the boys, a large hook was extended from the interior.

âLook, Frank!â Joe shouted. âThat man!â

Out of the bushes alongside the right-of-way dashed a burly figure. Timing his sprint perfectly, he halted just as the hook reached him. With a desperate grab he caught it, and was immediately drawn inside the car. The freight thundered on.

âThat must have been Turk!â Frank exclaimed.

By the time the Hardys reached the rails, the caboose had rolled by. There was no trainman in sight to hear their shouts or see their frantic signals.

Minutes later, Warden Duckworth and the driver caught up with them. Frank explained the strange getaway of the fugitive they believed to be Turk.

âIâll phone from my car,â the warden said, âand have the freight stopped and searched.â

He phoned the prison and instructed the telephone operator to relay the message to the railroad authorities. Then they drove back and waited in his office for word. When the report came, it was discouraging. The railroad police had opened car 138576 ten miles ahead, but had found it empty.

âTurk and his buddy inside may have seen you boys. They must have left the train somewhere along the stretch between where Turk got aboard and the next town. But weâll catch him. Prisoners donât break out of here and stay outâvery long!â

The Hardys remained in the wardenâs office for a while, hoping that there would be further news of the fugitive. None was forthcoming except that the driver of the National Meat truck was cleared. Finally they agreed that they should get home as quickly as possible and tell Mr. Hardy of Turkâs escape.

âThis convinces me that Flint is up to his old tricks again,â Mr. Hardy said. âThere has been a series of freight-train robberies throughout the country, and itâs up to me to figure out how to put a stop to them.â

âWho engaged you, Dad?â Joe asked.

âThe North American Railroad League, a group of railroad executives. Theyâve been losing a lot of property in train robberies, and believing that the thefts were the acts of a single gang, they think I can break up the racket.â

Mr. Hardy then went on to explain that the robbers, so far as he had been able to find out, had used either of two methods in their plan of operation.

âSometimes,â he said, âthey throw up a road-block at a strategic point, where the engineer canât see it in time to stop his train. In this way they create a wreck and make their haul during the confusion.

âAt other times they manage to send false messages by radio, and induce the train crew to switch certain boxcars to specified lonely sidings. Then they move in and loot them.â

âSounds like a pretty slick outfit,â Joe remarked.

âYes. Thatâs what makes them so tough to handle,â his father affirmed.

âDad,â Joe asked, âdo you suppose the phrase âtwenty wildcatâ is some kind of password?â

Frank, who had been listening quietly, offered an additional idea. âItâs possible that the railroad thieves have some kind of headquarters near where Capâs uncle was digging for fossils. Maybe a cache where they hide their loot.â

âThat would certainly account for their not wanting any strangers in that immediate area,â Mr. Hardy agreed. âThey may have been trying to discourage Bailey by holding him up on that first trip. As a matter of fact, they probably planned to steal the map his uncle left.â

The Hardys spent another half-hour discussing the case, then the boysâ father said he must get some papers ready for a plane trip to New York.

âIâm getting the eleven-oâclock flight, so Iâll be there first thing in the morning for a conference with the League officials,â he explained.

After Fenton Hardy had taken a taxi to the airport, the boys discussed their own trip, and the clothes and equipment they ought to take.

âI suppose weâll be on horseback a lot of the time,â Frank remarked.

It was almost midnight before the brothers had their gear packed. They were about to go to bed when the shrill ring of the telephone disturbed the quiet of the big frame house.

Frank answered the call. A womanâs voice, edged with hysteria, said, âThis is Mrs. Bailey, Frank. Iâve already called the police, but I think you should know what has happened here.â

âWhat, Mrs. Bailey?â

âTwo masked men broke into our house and ransacked it. They attacked my husband and left him unconscious!â

CHAPTER III

A Hazardous Take-off

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IN LESS than five minutes Frank and Joe were in their convertible, speeding toward Cap Baileyâs home.

âI hope Capâs not badly hurt,â Frank said worriedly.

By the time they reached the Bailey house, the police had already arrived. Frank and Joe dashed up the steps and were immediately recognized by the officer on duty at the door.

âMight have known you fellows would be on hand sooner or later,â he said with a grin. âWhereâs your dad tonight?â

Explaining that Mr. Hardy was on his way to New York, Frank asked about Cap Baileyâs condition.

âNothing serious,â the policeman assured the boys, and motioned them inside the house.

Cap was sitting on the sofa, holding his head, Mrs. Bailey beside him. A police sergeant was conducting the investigation, and Cap told him the details. He was glad to see the Hardys, and after a few words with them continued his account.

âMy wife and I had just returned from a concert, and I had gone upstairs,â he reported, âwhen I heard her cry out. I found her struggling as she was being tied up by one of the masked men. The other held a gun on me and told me to stand with my face against the wall. A moment later I felt a blow on my head, and thatâs all I know.â

His wife took up the story. âAfter that they turned the house upside down, searching for something. They must have been at it almost an hour. Cap was just beginning to stir again when they finally left, and I managed to struggle free.â

The police officer questioned Cap. âHave you looked over your things to see if anything is missing?â

âYes, but nothing much is gone. Only a duplicate map Iâd been making for a trip I plan to take this summer, but it wasnât complete.â

Frank and Joe exchanged knowing glances. The map of Wildcat Swamp!

âThey didnât get the original?â

âNo, I had that well hidden. You see, Officer, itâs a map of a property out West that may have some value to it.â With the promise that nothing would be made public, he told the sergeant the background of the situation.

Meanwhile, a policeman had been searching the entire house for clues. Now he came up to his superior.

âSergeant, we may be able to get some prints off that back kitchen window. It looks smudgyâunless the marks were made by one of the family.â

âNo, I washed every downstairs window today,â Mrs. Bailey asserted.

Hopefully, the police lifted all the prints they could find, and then left the house. The Hardysâ offer to remain overnight, in the event that the housebreakers might return, was welcomed by Mrs. Bailey, even though Cap thought it unnecessary. The boys, after calling home to let their mother know where they were, took turns sleeping, but the thieves did not reappear.

At breakfast Frank and Joe questioned the science teacher closely as to how many people might be aware of his intended trip.

âAs I told you, it was no secret at all,â he replied. âMatter of fact, a reporter from the Bayport Times got wind of it and came around for an interview. He wrote a long article for the paper.â

âGood night!â Joe cried. âDid he mention the location of Wildcat Swamp?â

âNo, I didnât tell him that. But I did mention the sign that my uncle had found, and the words âHere lie the bodies of twenty wildcat.â â

Their conversation was interrupted by the telephone. Cap answered it, and came back looking pleased.

âThe police were able to trace those fingerprintsâsome character named Willie the Penman.â

Frank and Joe almost shouted. âWillie the Penman!â

âHeâs that friend of Flint and Turk!â Frank exclaimed. âNow we know thereâs some kind of connection between Capâs mission and Dadâs case!â

They told Cap and his wife about the series of train robberies which Mr. Hardy had been engaged to investigate, and also about the prison break.

âI wonder if Willie or someone else in the gang happened to see that story,â Joe ruminated.

âIt certainly begins to sound as if Wildcat Swamp might be a hideout, with Turk joining Flint and Willie the Penman,â Frank observed.

âI take it you fellows are still interested in making the trip?â Cap asked with a grin.

âMore so than ever,â Frank said quickly. âTheââ

âAll I ask,â Mrs. Bailey interrupted with a worried glance at her husband, âis that you take care of yourselves. Iâm afraid that these men are desperate characters.â

Joe suggested they make the trip by plane instead of by car. âWe could even set out for a fake destination, to throw those guys off the trail in case they try to follow us,â he proposed.

Cap and Frank weighed the suggestion and found it thoroughly practical. It would be faster and would lessen the opportunity for interference.

âGreen Sand Lake might be the ideal destination to announce,â Cap remarked. âItâs well known as a searching area for fossil deposits, and itâs only about three hundred miles from Bayport.â

From there, they could go by rail to a place closer to Wildcat Swamp, procure mounts, and make the final stage by horseback. But this phase of the journey they hoped to keep secret.

Breakfast over, Frank and Joe went off to arrange details. First they contacted Jack Wayne, a private pilot who had become Mr. Hardyâs righthand man on charter flights. Jack was delighted to accept the assignment, especially when the boys outlined the reasons for the secrecy of the trip.

At home, though, they ran into trouble. During the boysâ brief absence, their Aunt Gertrude, who lived with them, had returned from a visit and had taken over on the home front. An elder sister of Mr. Hardy, the energetic woman had a determined air and an eye that missed little, yet the boys were very fond of her and liked to tease her.

âGoing away again, I hear,â she said as the young detectives were stacking their gear in the downstairs hallway, âFingerprint sets, radio sending-and-receiving set. Where to?â

Patiently but hurriedly they told her of having been asked to act as bodyguards and detectives for their science teacher, Cap Bailey.

âBodyguards!â Miss Hardy gasped. âArenât they the ones who always get shot first when someone is going to be assassinated?â

âDonât worry about us, Aunty,â Joe said, grinning. âWeâll duck between the bullets. And we need the radio so we can keep in communication with the undertakers just before the assassination.â

Take-off was set for early the next morning. Though the Hardys were at the flying field long before the time of departure, Chet Morton was there ahead of them, greeting Jack Wayne and bringing the travelers a box of candy as a parting gift.

âItâs only what I would like someone to bring me,â he remarked when they thanked him.

âLetâs open it right now,â Joe said with a laugh. âHelp yourself.â

Chet casually removed as many as one hand would hold. âIf you fellows need any help out West, just call on me. Well, Iâd better hurry home to work on the swimming pool. So long.â

He drove off and the three climbed into the cabin of the low-winged silver plane. Jack turned the switch and pressed the starter button.

Frank and Joe had flown with Jack Wayne many times before. They admired the way he handled his plane Skyhappy Sal.

After warming the engine for take-off, he swung the ship into the wind and lined up on the north-south runway, which paralleled the entrance road.

âAll set?â

The passengers nodded, and Jack shoved the throttle forward. The powerful engine roared, and the plane rolled ahead. As it gained speed, the runway flashing below its windows, the plane suddenly gave a lurch.

Jack yanked the throttle back and the engineâs roar died. But the planeâs speed was still high as he eased in the brakes. The next instant a heavy jolt shook Skyhappy Sal. Frank, sitting on the left, saw something dart from beneath the wing on his side and bound away.

A wheel!

It rolled into the entrance road, just missing a car and causing it to swerve dangerously.

In the cockpit Jack Wayne fought to keep his careening aircraft from reaching the road. Desperately he threw all his weight on the right brake. There was a loud, grating splatter as dirt flew up over the windshield.

CHAPTER IV

Fingerprint Tip

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JACKâS passengers clung desperately to their seats as the tilted plane spun and skidded through the soft earth. Inches from the busy roadway it came to a halt. There was a moment of silence.

âGreat work, Jack!â Frank found his voice.

Joe added his praise as Cap slapped the pilot on the shoulder. Only Jack Wayneâs skill had kept the plane from turning over.

âThis is a tough accident,â Cap said. âHow did it happen?â

âThe retaining collar slipped off,â Jack replied, after examining the landing gear. âBut I canât understand why. A cotter pin holds the collar tight and that keeps the wheel on the axle. I checked the plane this morning. There wasnât anything wrong with that wheel!â

Frank, Joe, and Cap looked at one another, the same question in each oneâs mind. Had someone tampered with the plane because of them?

âJack, would it be hard for a person to loosen one of these wheels?â Frank asked.

âAny good mechanic would know how,â the pilot answered. âWhy?â

Frank told him of the attack on Cap. It was entirely possible that someone had taken this method of trying to stop the trio from making the trip.

A determined gleam came into Jack Wayneâs eyes. âIâll get another plane. Iâm sure that the airport manager will let me borrow his. We shanât be delayed more than fifteen minutes.â

Upon hearing of their plight, the manager readily offered the use of his private plane. The travelers transferred their equipment at once.

This time the plane rolled smoothly down the runway, rose, and headed for Green Sand Lake.

The Hardys admired the unlimited view below. Joe noticed another plane, a mere dot on the horizon behind them. Ten minutes later the plane was still there, exactly the same distance away.

âFrank, do you think that pilot could be following us?â he asked.

Frank scanned the horizon to their rear.

âWhatâs the matter, boys?â Cap asked.

Joe explained, then told Jack. âHow about slowing down and letting him pass?â he suggested. âMaybe we can identify him.â

Jack throttled back but so did the pursuer, remaining far to the rear. All the boys could discern was that the plane was a low-winged, single-engine type similar to their own.

Soon Jack Wayne eased off his power and slanted down for a flawless landing at the small Green Sand Airport. The plane behind them made no attempt to land, and continued on its course.

âGuess we were mistaken about that fellow,â Cap observed as they unloaded the baggage. A few minutes later the pilot wished his passengers good luck and started back for Bayport.

Green Sand Airport was a desolate spot in rough country several miles from town. It boasted one large frame building, which was a combination hangar and administration shack.

âIâll try to arrange for transportation to the fossil area,â Bailey said.

He walked into the building, leaving the Hardys in charge of the luggage. A few seconds later Frank, peering upward, said:

âHere comes a plane. It looks like the one that was following us.â

The trim, low-winged craft droned around the field, making its traffic pattern, and floated in to a fast landing.

The pilot taxied in front of the boys, whirling his ship around and blasting them with a dusty slipstream. He cut the switch, and without so much as a nod, walked off to the hangar.

The stranger was a tall man with smooth black hair. But his eyebrows were surprisingly light, which made his eyes seem like black marbles. His nose looked like a bony blade stuck on his thin face.

âDonât like him,â Frank said crisply. âDid you notice his walk?â

âQueer,â Joe agreed. âHe slithers like a snake. I wonder who he is.â

âYou couldnât find out from his plane,â Frank observed, walking closer to it. âThe identification numbers are practically weathered off.â

âOr rubbed off on purpose,â Joe remarked. âAnd, say, look at that little insignia on the cowling.â

âA snake,â Frank whispered. âA snake eating a bird! It fits the fellow all right.â

A fuel truck rolled toward them. As it drew closer, the boys discovered that the beak-nosed pilot was riding with the driver. He alighted and strode up to the Hardys.

âWhatâs the idea of snooping around my ship?â

âWe were just looking it over,â Frank said casually. âWe wondered how you can fly without license numbers.â

âThatâs none of your business!â the man snapped. âItâs due for a new paint job at the end of this run, since youâre so worried about it. Now Iâll thank you to move on.â

He turned to the gas-truck driver. âGet me a taxi,â he said.

The driver nodded, completed his refueling job, and rode off with the pilot. At the same moment Cap Bailey pulled up in an old-fashioned rented car, and the boys put the luggage on its roof. Then they set off for the fossil area. Twenty minutes later they reached the famous spot.

âThe sand really has a greenish look,â Frank observed.

Cap smiled. âYouâll find that the study of fossils is pretty interesting. Paleontologists who dig for them are the detectives of the past, and fossils are their clues. You can tell from them what the climate was and if the place where they lie buried was dry land or ocean. The land weâre standing on was once deep beneath the sea.â

âThis far inland?â Joe asked.

âEven farther. This green sand was left behind by an immense sea that covered the eastern part of the country many centuries after brachiopods became extinct. By the way, this sand is very good fertilizer.â

âLike cheese, eh? When itâs green, itâs ripe!â Joe quipped.

The conversation turned to more serious matters. Cap asked the boys if they felt sure they had eluded any pursuers interested in stealing his map of Wildcat Swamp.

âI donât trust that pilot who flew in right after we did,â Frank answered.

âSince we seem to be watched,â Joe said, âmaybe we ought to rig up a booby trap.â

âWhat kind?â Cap asked.

âWell, if I were after any papers of yours, Iâd figure they were in that brief case you carry. Letâs take out whatâs important and leave the case in the car. Then we can walk out into the dry lake, circle around, and watch.â

âAnd in case someone takes that brief case, how about a little of this powder?â Frank suggested as he opened one of the bags and took out a plastic vial.

âWhat is it?â Bailey asked.

âA special dye powder. Weâll sprinkle it lightly over your brief case. Itâs the same color as the leather, but if anyone gets it on his hands, a blue stain will show up in a few minutes. And heâll have a terrible time washing it off.â

âWe may not catch the villain red-handed, but weâll sure catch him blue-handed.â Joe chuckled.

The trap was laid quickly and the car parked in plain sight. The three worked their way across the dry lake bed, around boulders, and through scraggly stunted brush toward the top of a hill.

But before they could reach the summit, a voice hailed them, âHey there! What are you up to?â

Cap and the Hardys stopped in their tracks and turned. A uniformed policeman had dismounted from a horse and was hurrying toward them.

âIâve been watching you,â the officer puffed. âYou donât act like fossil hunters to me. I patrol this area every dayâlots of professor guys get lost out hereâbut youâre not fossil men. You donât even have any equipment.â

Cap told the policeman of the trap they had just laid and why. âWill you help us?â the teacher asked.

The policeman became interested. âHm! Sounds exciting, and nothing exciting ever happens out here. My inspectionâs over. Iâll go along with you.â

He plodded behind the others up the low hill and crouched with them in a clump of thick brush.

Joe whispered excitedly after a few minutes, âLook!â

There was a movement in the weeds near the car. Suddenly two men stood upright and glanced about furtively. Then, swiftly and silently, they moved to the car and opened a rear door.

CHAPTER V

Into Perilous Country

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âDONâT jump them yet!â Cap Bailey hissed at Frank and Joe as they crept toward the car. âLet those thieves commit themselves!â

The two men snooped around inside for a moment or two. Then one of them picked up the brief case and began to paw through its contents.

âNow!â yelled Cap, and the Hardys and the police officer sprinted from cover.

Although both invaders were big, the policemanâs gun held them at bay.

âWhat were you fellows looking for?â Cap demanded.

âNothing,â the larger man muttered.

âW-weâre just hungry and thought there might be some food in this car,â the other said.

âLooks to me like you had a pretty good idea of what you wanted,â the policeman said sharply. âAnd it wasnât food.â

âIâm sure youâre right,â Frank agreed. âCan we get these fellows into custody around here?â

The officer produced two sets of handcuffs from his saddlebag. Then he asked Joe to ride his horse and ordered the two snoopers into the back of the car. He sat between them with his gun out and ready for action.

The jail was five miles away, but it did not take long for them to cover this distance, even proceeding at a pace slow enough for Joe to canter along behind. Reaching the small wooden structure which served as town hall and jail, they all went inside.

âWe didnât do anything. You canât hold us!â the big man protested when they were arraigned before the local magistrate.

âNames, please,â the magistrate ordered.

âUhâJake Johnson.â

âJim Jones. How long you gonna hold us?â

Frank and Joe pulled Cap into a huddle a short distance away.

âListen, Cap, the thinner chap looks just like a picture that Warden Duckworth showed us of Gerald Flint,â Frank whispered.

âAnd the other guy sure fits the description of Jesse Turk,â added Joe.

Cap considered. âWe donât want to let them know we suspect their identity. How about getting fingerprints from Warden Duckworth?â

The trio called the magistrate aside, explaining their suspicions and the necessity for concealing their identity.

âI canât hold them without a warrant,â the official told them.

âWe can prove enough now to give you cause to hold them until the prints arrive,â Frank said.

Going over to the huge man, he asked him to hold out his hands. Unsuspectingly, the man complied.

âYou see that blue stain on his hands?â Frank asked the magistrate. âThat came off the brief case belonging to our friend. I dusted the case with a special chemical powder before we left the car. Itâs proof this man was handling it.â

Snarling like trapped animals, the suspects were led away to cells in the rear of the building.

Frank put in a long-distance call to Bayport. Fenton Hardy, delighted that his sons had outwitted the men, promised to have the warden send the fingerprints to the Green Sand authorities.

âNow for Wildcat Swamp!â Joe said elatedly as they left the jail.

âLetâs see. From here we can get a train as far as Red Butte,â Cap remarked. âWeâll arrive there in the morning, and get our horses and supplies.â

They enjoyed a good meal in the trainâs dining car and discussed plans for suitable equipment. It was still early morning when they arrived at their destination, and Cap thought they had better use the hotel as a temporary headquarters. He led the way to Red Butteâs only hostelry, the Silver Saddle.

âBreakfast for three, hey?â the bewhiskered clerk greeted them. Learning they had just come from Green Sand, he said, âHave ye heerd the big news up there? It was on the radio early this morninâ.â

Frank nudged Joe, smiling, and Cap grinned too.

âCouple oâ guys broke outta that there jail,â the old man went on.

Frankâs head came up with a start, and Joe and Cap snapped to attention immediately.

âDid you say someone got away?â Joe demanded.

âTwo fellas, just stuck in there yestiddy for stealinâ outta someoneâs car, busted clear out last night. Got clean away!â

The three travelers looked at one another gravely. Turk and Flintâif it had been theyâwere on the loose again !

After some deliberation, the trio decided to leave as soon as possible for Wildcat Swamp.

âWhile weâre waiting for breakfast, Iâll send a message to Dad,â Frank said. âHe ought to be kept informed of whatâs going on. Suppose you two buy camp provisions while I contact him.â

âOkay,â Joe and Cap replied.

Frank hooked up the powerful little radio set. Switching to the secret frequency used by the Hardys, he called his home.

Fenton Hardy was disturbed when he heard of the desperadoesâ escape. He agreed that there was nothing for the boys to do but to proceed to the swamp as planned.

As soon as Joe and Cap returned to the hotel with their purchases, they all sat down to breakfast. Then the three went out to buy the digging implements they would need. At the general store the obliging clerk said:

âSince youâre heading into dangerous country, Iâd advise you to take along pistols. Only last week a trapper shot an ugly wildcat out there.â

âThanks for the tip,â Joe answered. âDo we need permits?â

âNot for pistols carried in plain sight.â

âThen weâll buy three.â

At the livery stable to which the clerk directed them, they were able to hire three sturdy saddle horses and a strong pack mule.

By midmorning they had packed their camping gear onto the mule and were ready to start off. Cap and Joe took the lead, with Frank bringing up the rear holding the animalâs rope.

âWildcats, here we come!â Joe cheered as they cantered from the main street of Red Butte and headed for the desolate-looking country southwest of the town.

âAccording to Uncle Alexâs map, itâs a good twenty-five miles to the swamp,â Cap called to the boys. âAnd this is pretty rugged country!â

The trail followed a swift little stream that wound back and forth through the uneven, rocky ground. The sun became scorching hot.

âWe wonât reach the first landmark until some time tomorrow morning,â Cap commented when they stopped for lunch. âThat will be a big tree near the ridge of a small mountain.â

âAny kind of a decent-sized tree would look good to me,â Joe said, perspiration soaking his shirt.

âYou sure get tired of looking at this brush, and sand, and rocks,â Frank agreed.

By late afternoon the extremely slow, steady plodding had brought them to a more fertile area, with scattered trees and lush grass. The long trek had taken its toll of riders and horses. All were tired, irritable, and jumpy.

âListen to those coyotes howl,â Joe muttered. âTheyâre the spooks of the prairie, all right.â

âWeâd better not go more than a couple of miles farther before we bed down for the night,â Cap advised. âOnce the sun sets here, it gets dark fast.â A short while later he called a halt.

Cap busied himself getting the sleeping bags unpacked and feeding the animals. Frank and Joe soon had a simple supper ready. After eating, Frank led the horses to the stream which had been their guide all day, and let them drink all they wanted. Then, after tethering them, he stepped back into the little circle of light made by the rekindled campfire.

âAll set for the night,â he announced. âHope it doesnât rain.â

âNot much chance,â Cap predicted. âLook at those stars. You certainly donât see them that bright back in the city, do you?â

âAlmost bright enough to travel by,â Frank remarked. âBut say, whatâs that light off there to the left?â

All three stood up and studied the distant glow.

âSomeone else is camping out here,â Frank decided. âMaybe Flint and Turk.â

Joe, impulsive as ever, cried, âLetâs ride over!â

It took only a few moments to bank their fire and saddle the horses.

Keeping well apart and permitting their mounts to pick their way in the darkness, the trio moved toward the light.

âItâs a campfire, all right,â said Joe. âLook!â

He was the first to spot the men crouched around the small blaze. âThere must be half a dozenâand horses, too.â

His mount had discovered the presence of other horses, and now let out a loud whinny. Immediately excitement broke out around the campfire. The men scrambled to their feet, ran to their horses, mounted them, and rode away quickly.

The young detectives wanted to follow them, but Cap insisted that it would be unwise since they themselves were not familiar with the territory. They carefully inspected the camp for clues but found none other than the hoofprints.

âDid you notice that one of the riders went off alone?â Joe asked. âI wonder why. The rest of them beat it in the opposite direction.â

âHere are the marks of his horse,â Frank said, turning his flashlight on the ground. âSmall hoofprints, too, as if it were only a pony and probably carrying a very light rider. Iââ

âAre you thinking what Iâm thinking?â Joe interrupted. âWillie the Penman?â

âCould be,â Frank replied. âAnd say, the prints lead in the direction of Wildcat Swamp!â

âYouâre right!â

âWe canât be too careful the rest of our trip,â Cap warned as they made their way back to their own campsite. Nothing had been disturbed, and despite their curiosity about the mysterious riders the three soon dropped off to sleep.

Joe was first to awake the next morning, and whipped up a solid breakfast before rousing the others. They paid a brief visit to the mystery camp before setting out for Wildcat Swamp, but gleaned no further information.

âAfter we cover the next mile or so we ought to start looking for that big tree on the map,â Cap spoke up. Since early morning the three had come quite a distance from the camp on the plain.

Six outlaws were crouched around the campfire

They were in hill country now. The trail wound through rugged terrain with patches of woodland. They rode along the rim of one small canyon and through the dry bed of another. After considerable time had gone by, Cap said:

âI certainly expected to see that big tree by this time. If Uncle Alex was right, we should be in sight of it, and thereâs nothing here but this scrubby pine.â

âThereâs no sign of a big tree but that old stump by the edge of that ravine,â Frank said, pointing.

Joe jumped off his horse to examine it, while Frank and Cap checked the map.

They were interrupted by a shout from Joe. âCome here! This isnât an old stump. The tree has just recently been cut down!â

When the others reached him, Joe was scraping away at the top of the stump.

âLook! This has been covered with mud to make it look like an old cut.â He pointed.

âBut whereâs the tree?â Cap demanded.

Frank looked over the edge of the ravine. âDown there,â he announced.

âThe tree was felled within the last couple of days, maybe only yesterday,â Cap observed.

âBy the men we saw at the campfire last night,â Frank conjectured.

âHow about the map that was stolen from you back in Bayportâthe unfinished copy? Had you put the tree on that?â Joe asked Cap.

âYes. It was one of the details.â

Frank stared at the teacher. âThen Iâm sure, Cap, this was an attempt to remove a landmark weâve been counting on to help us find Wildcat Swamp.â

The trio pushed on, stopping only a short time to rest their horses and eat lunch.

As they rode through the heat of the afternoon, Cap asked the boys if they had noticed the formations that looked like giant toadstools made of clay and sandstone.

âYes,â Frank answered. âI was wondering what keeps them from crumbling.â

âItâs the sandstone overhang which prevents the clay column from eroding,â Cap told him. âBack in the glacier age, they were separate deposits, and all the clay except that protected by the sandstone has eroded.â

The cavalcade skirted the edge of a deep ravine, the trail following a bench that dipped gradually toward a stream below and ended in a narrow grassy shelf.

Permitting the horses to drink and to graze on the scanty grass, the riders dismounted to stretch their legs.

Suddenly Joeâs voice rang out in alarm. âFrank! Look out!â

But his warning was too late. Before Frank could even get his arms up to defend himself, a tawny streak of fur and muscle launched itself through the air from the rocky ledge above.

It was an enormous wildcat!

CHAPTER VI

Deadly Danger

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THE big cat was in midair before Frank was even aware of it. He had no time to defend himself.

As the beast leaped at the boy, his horse instinctively reared and screamed. The action distracted the cat and gave Frank time to recoil a step, so that the animal missed its target.

Crack!

A sharp explosion came from behind, and the wildcat sank to the ground. Another quick report, and the snarling, spitting beast lay lifeless.

Frank turned and saw Joe, his gun still smoking, looking coolly at the still form of the wildcat.

Cap broke into a relieved chuckle and remarked, âI certainly knew what I was doing when I picked you boys as bodyguards!â

After making sure his attacker was dead, Frank pushed the carcass over the cliff. Then they took up the trail again.

âThis is the longest twenty-five miles Iâve ever ridden,â Joe remarked after a while. âI feel as if Iâve been in the saddle a month.â

Cap admitted that they had made slow progress, but he felt that they had done well enough considering the difficulties of the trail. Late in the afternoon they came to a spot where he suggested they make camp. In the morning, the ride toward Wildcat Swamp was resumed with renewed zest.

âThe next, and last landmark on the map,â Cap stated, âis a big needle rock with a balancing boulder on top. Itâs on a ledge, halfway down from an overhanging cliff to a long, sandy slope that ends in the swamp itself. The fossil should be somewhere in that sandy slope.â

Leaving the stream, which whirled away in a southwesterly direction while they continued west, the fossil hunters eventually came to the entrance of a long, narrow defile.

âWe must be getting close!â Cap said excitedly. âThe map shows this gap leads to the ledge above the needle rock.â

He went ahead through the passageway, with Frank following and Joe trailing with the mule.

âHere we are!â Cap exclaimed as he came out of the dark, shadowy defile onto a wide ledge.

A moment later the boys joined him on the ledge. To their right was a sheer cliff wall rising to a wide plateau.

To their left, the ledge fell away in a sloping, sandy decline, while straight ahead, at a turn in the ledge, stood the towering rocky column on which rested a huge, heavy boulder.

âLook at the size of that boulder!â murmured Joe in amazement. âItâs so delicately balanced it looks as if I could push it off.â

âYou might be able to at that,â Cap agreed as he studied the phenomenon.

âLook at that wooded mountain beyond the swamp,â Joe said. âThereâs a fire tower at the top.â

Just then Cap raised his hand for silence.

âListen!â

From the plateau above them came the sounds of a familiar, steady drumming. Hoofbeats!

âLetâs go!â Frank cried, spurring his horse back through the defile.

With Joe and Cap close behind, it was only a matter of minutes before he burst out through the dark ravine to the open terrain.

Just ahead of them was a single horse and rider. With a swoop, the trio surrounded him. To their surprise, the newcomer proved to be a young boy.

âHi, there!â Frank greeted the youngster, who looked to be about fourteen years old and handled a horse as if he had been born to the saddle.

âHi,â the boy returned. âWho are you?â

Cap Bailey explained that they were scientists, looking for fossils.

âThis is my motherâs property,â stated the youngster. âWho said you could dig here?â

âOh, then your mother must be Mrs. Sanderson!â Cap recalled that his aunt had stated in one of her letters that Mrs. Sanderson had given her approval of the exploration.

âThatâs right. Iâm Harry Sanderson.â

Cap introduced himself and the Hardys, and told Harry why they were there. He added that they would pay for the right to hunt fossils.

âOh, no, you wonât have to do that,â Harry assured him. âMr. Alex Bailey, when he first talked to my mother, promised that she would get all the money any fossils might bring.â

âWeâll go along on the same promise,â Cap assured the boy.

âWe liked Mr. Bailey,â Harry remarked. âHe seemed to be a nice man, but a short while after he settled things with my mother, he disappeared. We heard later that he got sick and died.â

âWe hope to finish the job he started,â Cap told him.

Frank and Joe cautiously questioned the boy, asking who lived in the area.

Harry smiled. âNobody but us and the sheriff-Lately, though, Iâve seen campfires and strange men. The other night a couple of âem stopped me and started asking a lot of questions. But I slapped my horse and got away.â

âWhat did the men look like?â Joe asked.

âBoth of âem were big, but one was the biggest guy I ever saw! Bet he could be a wrestler if he wanted to. The other man looked like he might be a lawyer or a doctor. He talked in a low voice.â

Frank and Joe looked at each other and knew what the other was thinking. The descriptions fitted Turk and Flint!

âIf those big hombres stop me again,â Harry said stoutly, âIâll get the Forest Rangers after âem.â

âOh, there are Forest Rangers in this section?â Joe asked.

âSure thing. They make regular visits through here, and they always stop at our ranch.â

âIs that the fire tower they use?â Frank asked, pointing to the top of the mountain rising beyond the swamp.

âNo. That old oneâs been abandoned. Thereâs a new tower you canât see from here.â

âThatâs good to know,â Cap commented.

âYes, and Sheriff Paulâs ranch isnât far from us, either. Heâs a good friend, too.â

âSay, Harry, you must know this territory pretty well,â Frank said. âAre we right in thinking thatâs Wildcat Swamp down there?â

âWildcat Swamp? Never heard it called that, or any other swamp around here.â

âAre you sure?â Cap was plainly upset by this revelation.

âThatâs Devilâs Swamp down there,â Harry said.

Cap and the Hardys looked at one another in dismay. Could they be off the track in spite of the map which they had followed so closely?

âWell, I have to get along home,â Harry said. âHope youâll all ride over to our ranch sometime. My motherâd like to meet you.â

âHow do we get there?â Frank inquired.

Harry pointed in a northwesterly direction. âThereâs a trail along the left side of that mountain.â

He slapped his pinto and was off across the plateau in a cloud of dust.

âSo this is Devilâs Swamp and not Wildcat Swamp,â Joe said in disgust. âWe come over a thousand miles by plane and train andââ

âWait a minute,â Cap interrupted. âIâm going to check this map again.â

For several minutes he studied the map in silence, then a smile of understanding slowly broke over his face.

âThis has to be the place,â he insisted. âThere couldnât be two such spots so much alike. Uncle Alex probably named it Wildcat Swamp on his own, not knowing what the local people called it.â

âThereâs one way to make certain,â Frank remarked. âThatâs to find the sign about the twenty wildcat.â

âIf itâs still here,â Cap said hopefully. âAnyway, letâs pick out a place to make camp. Then we can look around.â

After scanning the territory they agreed upon a wooded section of the plateau just above the mouth of the defile. All three occupied themselves with unpacking their gear and setting up the tent.

Cap and Frank found some suitable stones for a fireplace, and laid a small grate across the top. This done, the boys were eager to start exploring.

âDonât do any wandering around here without wearing your high boots,â Cap warned. âNo telling what youâll run into down at the swamp.â

Frank dug out the three pairs of thick wading boots which they had purchased in Red Butte and they all donned them, along with sturdy corduroy breeches. Light jackets would suffice, they decided, because the sun was still high in the sky.

Cap, still sure that this was the right spot and eager to see if there were any signs of his uncleâs work, told the boys to go ahead. They pigeon-toed their way down the sandy slope to the edge of the green marsh.

âWhat a mixture of growth!â Joe marveled at the lush, odorous tangle as Frank led the way into the swamp, keeping to the high hummocks and leaping over the black, watery, evil-looking expanses that spread everywhere.

âItâs amazing,â observed Joe, âhow we passed through such a barren region only a few miles away and wind up in a water-logged spot like this!â

âCap said thatâs the way this section of the country isâall extremes,â Frank said.

Excitedly Joe grabbed his brotherâs arm. âThere it is! The old sign!â

Nailed to a shaggy willow tree, almost completely enveloped with vines that grew up its trunk and wound around its branches, was an old, weather-beaten board. The Hardys cleared five feet of muck and landed next to the tree.

âThis is it! âHere lie the bodies of twenty wildcatâ!â Joe read.

They hurried back to camp. Cap was delighted to hear that the boys had found the sign. âFrom now on I can see that weâre in for some plain, old-fashioned hard work with pick and shovel.â

The trio unpacked digging tools, and then headed back to the spot on the slope which Cap had selected.

Swinging the heavy picks, they soon loosened the top layer of sandy soil. But then the harder work began.

âThis is really packed down,â Frank grunted as he swung the pick into hardpan and penetrated only a few inches.

They had worked for an hour when Cap unearthed an old tin can. He was about to throw it away when he took a second look and let out a yell.

âBonny Briar smoking tobacco! Thatâs the kind my uncle used to smoke.â

âThen weâre working in the right place!â Frank exulted. âUnless,â he amended, âsome other guy was around here who smokes the same brand.â

Cap refused to be talked out of his belief and dug with renewed energy. It was only a few minutes later when Joeâs pick hit into the dirt with an odd ringing sound.

âOuch!â he howled, wringing his hands as he dropped the wooden handle hurriedly. âI could feel that shock all the way up to my elbows!â

âWhat did you hit?â Cap queried.

âI donât know, but it sent a vibration right up the handle of this pick.â

More careful this time, Joe probed in the same spot, and gradually scraped dirt away from what appeared to be a length of metal.

As he worked, it became apparent that the object was heavy, rusted piping. Finally he uncovered its entire length.

âHow in creation did that get in here?â Frank asked, turning to Cap.

The young man was completely stumped. âUncle Alex wouldnât have used piping,â he mused. âAnd to the best of his knowledge, there had never been any previous exploration here.â

They were still studying their unexpected discovery when high above them they heard a great thud and a rumble. Frank, first to look up, gave a shout.

âThe boulder! Itâs toppled off the column! Here it comes!â

With a roar the great stone gathered momentum, sending smaller stones scurrying to all sides, then hurtling down the incline, straight to where the three were digging!

âLook out!â Joe screamed, jumping as far to one side as he could. Frank was already in midair, leaping to the other side.

With a crash the boulder tore across their excavation, pulling what seemed to be half the hillside with it, and thundered into the swamp with a tremendous splash.

Thankful to be alive, Frank and Joe gazed at each other, then looked for their companion.

But Cap Bailey was nowhere in sight!

CHAPTER VII

Skeletons and Schemes

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âCAP! Cap Bailey!â

There was no answer to the Hardysâ frantic calls. Following the thunder of the crashing boulder, the stillness was frightening.

âQuick! Weâd better clear away some of this rubble!â Frank ordered.

Rocks and shale of all sizes and shapes had broken loose in the landslide. Sand had been scooped from one spot and piled high in another. Desperately the boys rooted through the debris.

âJoe! It canât be! Cap just couldnât beââ

âFrank! Down there! Somethingâs moving!â

They tore wildly at the rubble until they had cleared Capâs face and shoulders. Groggy, the teacher drew in great lungfuls of air, until they pulled him free.

Finally he was able to sit up and move his arms and legs to show that he was unharmed.

âBoulder ... must ... have ... been ... tipped,â he said huskily. âGo... see ...â

Frank and Joe rushed up the slope but could find no trace of any person on the ledge. A quick glance revealed no one near the rock column from which the boulder had become dislodged.

âLetâs take a look on the plateau,â Joe said, and they hurried along through the defile.

Atop the flat ground, they saw nothing at first that could be connected with the fall of the boulder. Then off toward the trail around the left side of the mountain, Frankâs keen eyes spotted a cloud of dust.

âTwo riders!â he shouted.

The Hardys knew they could not hope to overtake the men.

âAnyhow, weâve got to get back to Cap,â said Joe.

When they reached the rock ledge, the boys could see that Cap felt considerably better. As they skidded down the incline toward him, he gestured excitedly.

âLook at this!â he exclaimed, and pointed to a large object he had picked out of the debris.

Frank and Joe examined it curiously. âWhat is it?â Frank asked.

Cap spoke triumphantly. âUnless Iâm very much mistaken, itâs a bone from the leg of an ancient horse. It was turned up by the boulder when it ripped down the hill.â

âAn ancient horse? You mean that there were prehistoric horses in this country?â Joe asked.

âI thought the horse was a comparatively recent animal,â Frank chimed in.

âOh, no, the horse has been part of the earth as far back as man can tell. As a matter of fact, the evolution of the horse is one of the interesting mysteries of paleontology.â

âWhat do you meanâmystery?â

âNo one has figured out why the horseâa much smaller one than the present kindâlived here from prehistoric time until the Pleistocene period, then became extinct. The horse as we know it today was imported.â

âIf this fossil is from one of the earlier breed,â Frank observed, âit must be mighty valuable.â

Bailey nodded. âIf Iâm right, it could mean there may be many valuable fossils here besides the prehistoric camel my uncle discovered.â

Cap was so excited that all thoughts of his brush with death were forgotten. When the boys told him of the two riders they had seen in the distance, he merely nodded.

âIf they did tip the boulder, actually they did us a favor. Look at the digging they saved us.â

âBut if they continue to make attempts on our lives,â Frank said, âweâll have to be on guard every second.â

âIs there any possibility of getting help in this excavation job?â asked Joe.

Cap shook his head impatiently. Elated by the discovery of the fossil, he was ready to start work immediately.

âIf those men were trying to stop us by toppling the boulder, they probably think weâre dead, and wonât be coming back,â he added.

Frank and Joe, eager themselves to see what other fossils might be turned up, fell to work in earnest.

For several hours they sweated as they dug deeper into the sand and hardpan.

âIâve hit something!â Frank suddenly called out. When it was uncovered, Cap Bailey was enthusiastic.

âBoys, Iâd bet my last shirt that this bone was once part of the shoulder structure of the ancient camel Uncle Alex thought heâd found!â

âLooks like an oversize ham bone that some prehistoric dog buried here,â Joe said wryly. He sat down in the sand and propped his weary head on one grimy fist. âYou really have to be interested in fossils to work this hard,â he groaned. âIâll never think of geologists and scientists again as old fuddy-duddies.â

Cap and Frank burst into laughter.

âBetter buck up, Joe, weâve barely started.â Cap clapped him on the back and asked him to carry the ancient bones up to their permanent camp, and to put the fossils under a protective tarpaulin.

âWhat are we bothering to cover these things for?â Joe queried. âNobodyâs been taking very good care of them for a couple of million years.â

âExcept nature,â Cap said. âSheâs been protecting them from the weather all this time.â

Joe nodded and set off across the slippery sand and through the defile.

Cap and Frank picked up their shovels and resumed work, chopping out large chunks of near-petrified sand. The pit grew deeper and deeper. They were working in silence, intent upon the task at hand, when Frank began to feel uneasy.

Where was Joe? He had been gone much too long for a mere trip to camp. Frank climbed out of the excavation and scanned the slope. He could not see his brother.

Worried, Frank hurried toward the plateau. Had something happened to Joe?

Sensing trouble, Cap followed Frank, reaching the camp a few minutes later.

âJoe doesnât answer,â Frank said. âBut,â he added, pointing to a tarpaulin wrap, âthere are the fossils. Heâs been here.â

âHow about the horses?â Cap asked, and quickly investigated the tiny meadow where they had tethered the animals. All three horses and the pack mule were grazing contentedly.

âIâll try our distress signal.â Frank gave a long, piercing birdlike whistle. It was the secret whistle he and Joe used when in trouble.

But no answer came, and again Frank gave the shrill, high-pitched call. Listening intently after it ended, all he and Cap could hear was the breeze as it gently moved a few leaves high above them.

âBut what could have happened to Joe?â Cap asked. âIf he met with any sort of trouble, we should have heard some kind of sound.â

After discussing the situation, they decided on a systematic search of every foot of ground between the camp and the slope. They had got as far as the ledge when Cap held up a warning hand.

âDo you hear something?â

For a moment there was only silence. Then, almost as if from under their feet, in the depths of the earth, they heard:

âFrank! Fra-a-a-a-nk!â

The voice was so low and indistinct that Frank thought he might have imagined it. But a look at Capâs excited face convinced him that his companion had heard the call too.

Where was it coming from?

After several minutes of frenzied search they had the answer. A flash of light from between two huge rocks just below them at the very edge of the slope caught Frankâs eye.

âDown there!â he cried excitedly.

He and Cap peered into the crevice. This time a light shone squarely in their eyes, and they realized that they were staring into the beam of a flashlight.

âHey! Come on down!â It was Joeâs muffled voice. âItâs a cave, and somebodyâs here!â

Examining the opening, Frank and Cap realized that a man could easily squeeze through it. Rigging a stout rope around a large boulder as a means of ensuring their exit, they wriggled down the rope and into the passageway. In a minute Frank stood beside Joe on the floor of a sizable cavern.

âYouâre okay? You didnât have an accident?â Frank asked.

âNot exactly,â Joe answered. âI tripped, fell off the ledge, and rolled down here. When I saw this cave, I thought Iâd investigateâand look!â

He pointed with his flashlight to one of the recesses of the cave. Propped against the sloping wall was a skeleton!

âNice cave mates you pick for yourself, Joe!â Frank said jokingly. He spoke lightly, but a shiver ran down his back as he gazed at the skull.

âListen, fellows, that man probably died from suffocation or starvation in here,â Cap said. âI wonder whether he had been living in the cave.â

âAnyway, he had plenty of equipment with him,â Joe said. âSee?â His flashlight picked out a pile of long, rusty iron pipes near the skeleton.

âSay, theyâre the same kind as the pipe you found on the slope, Joe!â Frank cried. âThis old geezer must have brought them down here for a purpose.â

âHe probably was a prospector,â Cap decided. âI wonder what he planned to doâdrain the swamp?â

âBut what for?â Joe asked.

âMaybe he had panned some of the slope,â Frank said, âand believed it might be a good prospect for placer mining.â

All three joined in rummaging around the cave with their flashlights. Cap was about to suggest that they return to the surface, when Frank excitedly cried out:

âCome here, quick!â

Hurrying over, they found him in a dark corner. He had spotted a gleaming new pistol.

âSomeone else has been here, and not long ago,â he announced. âThereâs not a speck of rust on this gun.â

Carefully Frank wrapped a handkerchief around the weapon and picked it up. By the beam of his tiashfight, they all could clearly see the smudges of someoneâs hand along the barrel.

âI have that fingerprint powder in my pocket, I think,â Joe said. âLetâs see what those prints look like.â

He dusted the smudges, and Frank examined the clear prints. There was a familiar swirl on one that looked like a thumbprint.

âDoesnât that remind you of the thumbprint of a certain character named Willie the Penman?â Frank asked excitedly.

âIt sure doesâon the kitchen window of Capâs house,â Joe replied.

âIf so, whatâs our next move?â Cap asked.

âTo prove our point,â Frank replied.

He proposed that they leave the pistol in the cave, on the chance that the owner would return, and they could capture him then.

âWe can watch from above,â the young sleuth suggested.

âGood idea,â Joe said, and Cap agreed. Making sure they had left no telltale traces of their presence, they climbed up the rope through the cleft in the rocks to the ledge above.

All agreed that further digging for fossils must wait upon this new development. There was a good chance that the owner of the pistol had been watching them.

Evening chores were split up among them. Cap hid the precious relics, while Frank prepared supper, and Joe watched the cave entrance from a spot in the shadows. The trio ate supper in Joeâs hideout.

âWeâd better stay right here tonight,â Cap proposed.

By dusk the three watchers were ensconced in a makeshift shelter. Lying prone, they could see every bit of the slope around the entrance to the cavern. A full moon provided all the illumination needed.

âWeâd better agree on shifts,â Cap suggested, and it was decided that Frank would have the first watch. Joe would take over at midnight, and Cap at three in the morning.

There were no disturbances during the night and at six oâclock Cap awoke both his companions.

âI was sure somebodyâd come back for that pistol,â Joe said, disappointment in his voice. âWell, Iâm going down to have another look in the cave.â

âIâll go with you.â Frank crossed the slope with his brother and descended to the floor of the cave. A moment later the boys looked at each other in astonishment.

âThe pistolâs gone!â they cried simultaneously.

âBut how could anyone have taken it?â Joe demanded. âNot a soul came near the cave.â

âUnless,â Frank said, âthere is another entrance.â

It took only five minutes for the boys to investigate Frankâs theory. After probing every niche and cranny of the walls, he found a loose boulder which looked as if it had been set in one corner for a purpose. Moving it a bit, Frank saw daylight.

âCome on,â Frank motioned, and the boys crawled through.

They found themselves farther along the slope, around the corner from the spot where they had lain watching all night!

âWhat a couple of duds we turned out to be,â Frank said in disgust. âAnd what a laugh Willie or whoever it was had on us!â

âI wonder if he saw us lying there in wait,â Joe pondered.

Replacing the stone that covered the entrance, they called to Cap and showed him the second underground entrance. The teacherâs reaction was almost identical with Frankâs, and he added, âThis place may be riddled with secret caves, and eventually bullets, if we donât watch out.â

A short conference produced one decisionâto radio Fenton Hardy and tell him that Willie the Penman might be in the neighborhood of Wildcat Swamp.

Frank unpacked the powerful sending-and-receiving equipment. They surveyed the terrain for a good working spot.

âBelow this mountain ridge, weâll certainly have trouble getting a good signal,â he murmured, and decided that the only possible way to make contact would be to use the self-inflatable balloon they had brought to carry the antenna aloft.

Soon the little gas-filled bag was high in the sky, trailing its aerial wires. Frank tuned in the secret frequency that the Hardys used for family communication. He was about to give it up as hopeless when suddenly a voice said:

âFenton Hardy speaking. Come in! Come in!â

Quickly Frank reported that they were well, and then told his father of the latest developments.

âWill you get prints of Flint, Turk, and Willie from Warden Duckworth and send them to Red Butte as soon as possible,â he requested. âWeâll check them with the ones on the pistol we found last night.â

His father agreed.

âHow about the train robbers?â Frank asked. âAny news?â

âI have a hot lead Iâd like you boys toââ

Mr. Hardyâs voice faded completely. There was not a sound from the receiver.

Startled, Frank glanced toward the airborne antenna, just in time to see the balloon, deflated, plummet to the earth.

Now there was no chance to find out what the detective had intended to say!

CHAPTER VIII

Ordered Out

âWHAT happened?â

Capâs cry was hardly out of his mouth when Joe and Frank were racing off to retrieve the deflated bag. It dropped out of sight, but by following the dual cord which had secured it to the set and carried the antenna line, they soon located it. The balloon hung limply from the branches of a tall pine. Frank shinned up, unfastened the bag, and brought it below for examination.

âPunctured,â he said. âLook at those holes.â

Cap came running up just in time to hear Frankâs remark.

âBut howâso high up in the air? Nobody could throw a stone that farânot even a baseball pitcher!â

Frankâs face was grave. âI believe someone fired a bullet through it.â

âBut I didnât hear any shot,â Joe objected. âDid either of you?â

âThe shot could have been fired from the other side of the ridge,â Frank commented.

Cap nodded. âEspecially if the wind were blowing the other wayâwhich it isâwe wouldnât have heard the shot.â

âI wonder,â Frank mused, âwhether some cowboy took a potshot at it just for fun, or if our friend Willie did it deliberately.â

âI wish we could find out just what is behind all these goings-on,â Cap said. âIt doesnât seem likely that a gang of ex-convicts would be worried about our finding a few fossils. What can be the real secret of Wildcat Swamp?â

âIt must be pretty valuable for somebody to go to such great lengths to protect it!â Frank stated with a tight smile.

Slowly they walked back toward camp, winding the antenna wires on the spindle as they went along. Even though the balloon itself was useless now, the aerial could be salvaged.

They had almost reached the tent when they heard the sound of hoofbeats behind them, coming down the ravine. Tight-lipped, they waited for the horsemen to appear.

âOh, it must be the Forest Rangers,â Joe announced, relaxing, as three green-uniformed riders appeared.

The one in the middle was short, wiry, and gruff-looking. To his left was a medium-sized man, and the third ranger, also short, had a peculiarly flat nose.

âWho are you birds?â asked the wiry leader.

âWhat are you doing in these parts?â the flat-nosed one spoke up.

Courteously, Cap introduced himself and the Hardys, explaining their business in the community.

The leader, who apparently was indifferent to the fit and condition of his uniform, nodded.

âWell, I have bad news for you. Youâre going to have to call it all off.â

âWhat do you mean?â Cap demanded.

âI mean that weâre ordering you to pack up your stuff and clear out of this territory.â

âBut we have permission from the owner!â Joe protested, stepping forward. âShe knows all about this expedition!â

âI said youâll have to pack up and clear out,â the spokesman retorted in a rasping voice. âIf you must know, this is an order from the government.â

âFor us to get out?â Cap asked unbelievingly.

âEveryone around here has been ordered to move all belongings away,â the ranger continued. âItâs going to become a government reserve.â

In dismay, Cap and the Hardy boys looked at one another. If the government had closed the territory, there was no alternative for them but to leave. Cap begged for an extension of time, but was turned down.

âGet on the trail,â the ranger ordered.

He and the other men followed the fossil hunters to their camp and stood by to see that they packed up. Discouraged, the three went through the process of folding the tent and dismantling all their permanent fixtures.

âGet a move on! We havenât got all day!â the leader of the rangers commanded, watching the proceedings with a grim smile.

âAll right, but we have to pack some of this stuff carefully,â Frank answered as he began to stow away the radio equipment.

âSay, son, have you got a state license for that?â the officer asked. âIf you havenât weâll just have to take it.â

Frank was astounded. âState license? I never heard of such a thing. I have my regular radio license.â

âThatâs not enough. You need a special one around here,â the spokesman announced. âShort wave, ainât it? Yep, thatâs the story. Pick it up, men,â he ordered the other rangers.

âBut you canât do that!â Joe sputtered. âThe radio belongs to us.â

âSure, sure, and you can have it back,â the man replied, âby calling at our district office for it next month.â

Despite more protests, the rangers, fingering their holsters, coolly appropriated the set. Discouraged and quiet, the trio rode off toward Red Butte, with the three men in uniform following them to see that they left the area.

Cap was downhearted because he had come close to finishing his uncleâs task. Although he had the two pieces of fossil carefully stowed aboard the pack mule, he was sure other parts of the ancient camel remained on the slope. What a thrill it would have been to find a whole skeleton!

âAll right now, just keep going a good ten miles before you stop,â called the leader of the rangers. âAnd after this, do your fossil digging some place else besides Wildcat Swamp!â

There were no words spoken among the three as they jogged along. But as soon as they had put sufficient distance between themselves and the rangers, they halted and held a council of war. It was decided not to put more than a mile between their new camp and the swamp.

âIâm not going to leave here until this whole mystery is solved,â Frank said determinedly. âGovernment reserve or not, if Willie and Turk and Flint have anything to do with this place, Iâm going to find out about it.â

âMe, too,â Joe added. âI never thought of it, but we probably should have told the rangers our suspicions.â

âAfter we compare the fingerprints from the pistol with those your fatherâs sending,â Cap spoke up, âweâll have more to go on.â

They dropped off the trail and dismounted near a small brook. Doggedly they went about the business of establishing their new base in a well-concealed spot.

âDad said heâd send the prints by air mail,â Frank commented. âTheyâll probably be in Red Butte before we can get there ourselves.â

Cap looked at the Hardys more spiritedly than any time since they had been ordered away from the region of the swamp.

âSay, it might be a good idea if I started tonight for Red Butte,â he said. âThen Iâd get there just in time to pick up the letter, and could head back here as soon as I had it. Traveling by moonlight ought to be safer than in broad daylight, the way things are going.â

Much as they disliked seeing Cap go off alone, the boys had to agree that his idea made sense.

âIn the meantime, we can guard the gear and keep our eyes open for those jailbirds,â Frank said.

After a quick supper they helped Cap saddle up, and made sure he had enough provisions to last the trip. After he had ridden off, the boys, deciding against a campfire, crawled into their sleeping bags and lay down.

âI certainly didnât think much of those rangers,â Joe remarked with a yawn. âI always thought that rangers were well-uniformed, neat, and trim. That little mangy guy in the middle was the sloppiest-looking ranger I ever saw.â

âSay, Iâve been thinking about that very thing,â Frank retorted. âA lot of things those rangers said just didnât ring trueâlike that license business about the radio.â

âThey sure were nasty and Iâve always heard that rangers are polite,â Joe said, recalling particularly their leaderâs parting shot. â âDo your fossil digging some place else besides Wildcat Swamp,â â the boy repeated in a voice imitating that of the ranger.

Frank suddenly sat up. âJoe! Do you realize what that ranger said? Wildcat Swamp!â

âSure. What about it?â

âDonât you remember Harry Sanderson telling us itâs called Devilâs Swamp?â

Joeâs eyes grew round as he realized the implication. âLocal rangers would probably have called it that, too.â

âExactly. Those men might be phonies. Letâs get back to the slope and see whatâs going on!â

Quietly they rode through the brush, keeping off the trail as much as possible, until they were less than half a mile from the upper mouth of the defile. There they tied their horses, and went on afoot.

Down the defile they crept, listening for alien sounds. In a short time they were standing on the rock ledge above the slope. The moon had been blotted out by a cloud a moment before, so now there was blackness all around them.

Joe grabbed Frankâs arm. âLook down there!â

Shining from the entrance to the cave was a bright light!

CHAPTER IX

Lost!

âLETâS crawl down and look in the cave!â Joe whispered.

âOkay. But take it easy. There may be a guard, and when that cloud passes over, weâll be good targets for him.â

Stealthily the Hardys crept down the incline. It was treacherous going in the darkness, without the rope, and complete quiet was absolutely necessary .

âCan you see anything?â Joe whispered as they finally reached the lip of the opening and Frank peered cautiously over it.

The answer was a tightening of Frankâs grip on his arm. Wriggling closer, Joeâs eyes searched downward into the cavern, and he nearly cried out.

Below them were the three rangers!

The boys could hear the murmur of their voices but could not make out their muffled conversation.

Unable to determine exactly what the men were doing, Joe tried to squirm around for a better view.

On the very edge of the opening, his elbow slipped. Before he could prevent it, a stream of pebbles and stones cascaded down into the cave!

âWhatâs that?â grunted one of the men.

The boys heard startled exclamations as the rangers in the cave jumped to their feet.

âSomeoneâs up therel Getâem!â

Furious that they had been discovered, the Hardys scrambled up the slope. There was no use trying to be quiet now, and they slipped and stumbled as they made their way toward the ledge.

Behind them, there was an uproar as the rangers gave chase. Just then the moon came out from behind a dark cloud and the ledge was bathed in moonlight.

âRun faster!â urged Frank as they headed for the shadows of the defile.

There was hardly need for Frankâs advice. Joe already was tearing along at top speed. Just as they reached the entrance of the rocky passageway, there was a loud report behind them. Pt-s-s-s. ee-ee!

A bullet whistled overhead, then another, and another. The sound of flying lead lent wings to the feet of the Hardy boys.

The sound of flying lead lent wings to the Hardys

âStay off the trail! Cut across the other way!â Frank hissed.

Joe let his brother pass him. Frank dashed through a tangle of underbrush, up the steep slope of the defile, and into the woods. They struggled over rough ground, running into low-hanging branches, tripping over roots, falling to hands and knees innumerable times.

A wild search was made with flashlights by the rangers behind them. Again and again the boys dodged the beams. Finally they were able to throw off their pursuers, and they breathed a sigh of relief when all sounds of the chase ceased.

Frank and Joe stopped to rest. After a breathless moment, Joe found his voice to express new concern.

âWhat if they find our horses!â

âJust hope that they donât. Anyway, weâre safe! I wonder where we are. Iâve lost my bearings completely.â

For some time they searched in vain in the darkness for a familiar landmark, but in the shadowy woods there was little they could see. Joe was about to suggest that they give up looking for camp until morning, when Frank whispered:

âSSS-s-st! A light!â

Up ahead, they could see a dim light bobbing in midair, as if it were suspended from nothing.

A few seconds later there came the soft clopclop of a horseâs hoofs slowly picking a path among the trees.

âMaybe the riderâs meeting someone here,â Joe said.

Quickly the Hardys found cover, and waited. Within minutes the rider came abreast of their hiding place. The soft glow of the lantern he held lit up his youthful features.

Harry Sanderson !

âGolly, are we glad to see you!â Joe greeted him. âWeâre lost.â

âIâm just as glad to see you!â the boys replied. âI was on my way to find you.â

Frank explained what had happened, from the time they had been ordered out of the fossil area to the present moment. When he heard their description of the rangers, Harry said he did not know the men. And oddly enough, he had never seen the cave.

âYou didnât tell us Wildcat Swamp was to become a government reserve,â Joe chided him.

Harryâs eyes flicked wide open in amazement. âItâs not true. I mean, my mother and I havenât heard anything about it. Something mighty funnyâs going on. A man came to our ranch this evening to buy the swamp.â

Harry went on to say that a stranger had dropped in with papers to show his mother that Devilâs Swamp and a lot of the ranch belonged to someone else, and the man was going to buy it from the real owner.

Frank and Joe were baffled by Harryâs revelations. They began to realize that a great deal was happening in the Wildcat Swamp area that was mysterious and which their father would want them to investigate.

âAll my mother really owns,â Harry went on, âis the house and a few acres around itâat least thatâs what the man said.â

âWho was this man?â Frank asked, his eyes flashing with indignation,

âHis name is George Moffet. I never saw him before. Guess he doesnât live around here. He was a little guy, pale and beady-eyed.â

âWillie the Penman, Iâll bet!â Joe exclaimed.

âWillie who?â Harry asked.

Without telling him that Willie was an ex-convict, Joe said he had acquired the name because he could imitate other peopleâs signatures.

âIf your caller was Willie, he probably drew up the papers himself,â Frank said. âHarry, you tell your mother not to give up any papers and not to sign any unless we see them first. She shouldnât even show her deed to this impostor. Keep it locked up in a safe place. Hurry!â

âThanks a lot, fellows,â Harry said. âI knew youâd help me.â He said good-by and rode off.

The Hardys continued their search for their horses. They found the animals safe. Apparently the rangers had departed.

Quickly the boys leaped into their saddles and reached the camp without further adventures.

To their relief, nothing had been disturbed, and once more they crawled into their sleeping bags. Next morning Frank and Joe discussed the strange events of the previous evening.

âDoesnât it strike you as strange that three new rangers were sent here in addition to the others already located in this area?â Joe asked Frank.

His brother nodded. âAnd itâs not natural for men in that position to be whispering in a cave. Iâd like to sneak back to the swamp in daylight and see whatâs going on.â

âGo ahead. Iâll watch camp. We canât take a chance on having our stuff stolen.â

As soon as they had eaten, Frank went off to reconnoiter. His careful approach through the defile and the ledge was effort wasted, he discovered. There appeared to be no one around, and no trace whatever of the men who had been there only a few hours before.

Without Joe to stand guard for him outside, Frank did not attempt to enter the cave. But he played his flashlight into both entrances and satisfied himself that they were vacant. The only explanation he could think of was that the rangers might comprise a special group to evacuate people from the new government reserve. If the Sanderson ranch actually was to be turned into a reserve!

Back at camp, he said to Joe, âAs soon as Cap gets back I think we can take a chance digging again. As long as we donât carry away any fossils, there wonât be any harm in looking for them.â

Joe agreed. In the meantime, he wanted to keep busy.

âI think one of us had better get in touch with Mrs. Sanderson,â he said. âHarry may have been stopped before reaching home.â

âIâll stand guard here this time,â Frank said. âYou ride over to the ranch.â

With Harryâs directions to guide him, Joe started out for the Sanderson ranch house. The path led over fairly rough country on the other side of Wildcat Swamp. Joe saw no evidence of grazing cattle, though there were occasional grassy stretches that would have afforded pasturage. He scared up several rabbits, and took a potshot at a fox about to devour one.

Presently the way led up through another rocky defile, similar to the one near camp. Joe was halfway through this narrow ravine when he heard the sound of horseâs hoofs from up ahead. The horseman was coming straight in his direction and there was no place to hide from a possible enemy.

The strange rider bore down on him from around a curve in the traiL Twenty paces ahead the newcomerâs horse shied, stumbled over a loose stone, and threw his rider headlong.

Like a sack of meal, the rider struck the ground and lay still.

âThis canât be a trick,â Joe thought to himself. âHe hit the earth too hard!â

Cautiously, nonetheless, Joe dismounted and approached the fallen rider, who had not moved.

Joe took hold of him, turning the rider over on his back.

It was Chet Morton!

CHAPTER X

Three Odd Letters

âCHET! Chet Morton!â Joe shouted in disbelief.

His friend did not stir. Joe flipped the top of his canteen and held the cool water to Chetâs lips. The boy moaned and tried to rise.

âJoe! No, it couldnât be. I guess Iâm dreaming. Iâm still kayoed.â

âYouâre not dreaming, Chet. What are you doing way out here?â

Chet rested several seconds before replying.

âMortonâs Pony Express. Modem variety,â he said cheerfully. âBoy, that spill knocked the wind out of me. I have a message for you guys. Several, in fact.â

âIs Dad okay?â Joe asked apprehensively.

âOh, sure. Your dad and I flew to Red Butte together yesterday afternoon with Jack Wayne.â

âYou and Dad?â

âYeah. Heâs hot on the trail, I guess. Those train robbers are going to the hoosegow.â

âWell, whatâs the news?â Joe asked eagerly.

âI have the fingerprint pictures you asked for,â Chet said as he struggled awkwardly into his saddle.

âCome on, Chet,â Joe said. âIâll show you the way back to camp and while Iâm there Iâll compare those prints with the ones we found on the pistol.â

As they rode along, Chet told Joe the reason for his sudden trip to the West.

âYour dad thought Iâd enjoy it,â he began. âAnd also, he didnât trust anyone else to give you an important message. He thought Sheriff Paul probably would know where you were, so just before he took the midnight train, he told me to contact the sheriff and have him take me to Wildcat Swamp.â

âWhere did Dad go?â

âHe was as secretive as usual,â Chet said.

âDid Sheriff Paul bring you?â

âNo, he wasnât at his office, so I rode out to his ranch. But he wasnât there either. Nobody was.â

âThen how did you find this place?â Joe asked.

âA nice kid reined up in front of the Paul ranch just as I was about to leave,â Chet said. âName of Harry Sanderson.â

âWe know him.â

âYeah, he told me you did, and he showed me how to get here. Knows all the short cuts. And boy, he can ride like the wind!â

Chet paused for breath, then asked, âHowâs Cap?â

âAll right, I hope, He went to Red Butte. Funny you didnât see him at the hotel.â

âHe wasnât registered.â

This turn of events worried Joe. Had Cap been attacked on the way to town?

âNothing seems to be turning out right on this expedition,â he told Chet, and brought him up to date on all that had happened.

âAt least you now have a copy of the fingerprints you wanted,â Chet remarked with pride.

Arriving at camp, Joe flung himself from the saddle. âHi, Frank!â he yelled. âLook what I found along the trail.â

âChet! Howâd you get here? You look as if youâd ridden all the way from Bayport.â

âI had a spill,â Chet confessed. Then, repeating his mission, he pulled a packet from his jeans and handed it to Frank.

Eagerly Frank tore it open. It contained magnified copies of three sets of fingerprintsâTurkâs, Willieâs, and Gerald Flintâs. The Hardys at once compared them with those taken from the pistol.

âLook at this whorl,â Joe cried excitedly. âNo mistaking it. The gun we found in the cave was once in the hands of Willie the Penman. And Iâll bet itâs in his shoulder holster right now!â

Chet let out a whistle. âHeâsâheâs after you guys?â

âGuess he is,â Frank said.

âIn that caseââChet gulpedââIâd better get back to Bayport and finish digging our swimming pool.â

âBefore you eat?â Joe needled him,

Chet grinned. âIâll stay till morning. Got to get some rest, anyway.â

âHold it!â Joe said suddenly. âDid you give us all of Dadâs messages?â

âHey, itâs good you reminded me,â Chet answered. âI forgot something.â

âWhat?â

âYour dad wants to see you.â

âWhen?â

Chet pushed his Stetson back and scratched his head. âLetâs see. Just before midnight on the seventeenth.â

âWhere?â Frank asked impatiently.

âOn the railroad siding near Spur Gulch.â Chet pulled a map from his pocket and handed it over.

âFrank, thatâs real news from Dad!â Joe exclaimed. âSomethingâs doing. A trap for the train robbers, or I miss my guess.â

âCould be,â Frank said. âI hope we can dear up some of the mystery around here before we leave to meet Dad in two days. I think we ought to find Sheriff Paul and tell him about Willie the Penman. And we still have to see Mrs. Sanderson.â

During the evening the boys waited expectantly for Cap, hoping someone in town had told him of Chetâs arrival. But Cap did not come.

âIâm afraid he never reached Red Butte,â Frank said fearfully. âAnd now that we know Willie the Penman is in the neighborhood, Iâm worried.â

With concern on his face, Chet pulled a bright bandanna from his pocket and mopped his brow.

âHonest, fellows, I have to start back for Bayport in the morning.â

âBut as long as you are here, wouldnât you like to help us dig up a camel?â Joe suggested.

âA what?â

âThatâs right. Weâve found one.â

Chet began to weaken. âWell, I might stay a day or two.â

When morning came and Cap still had not appeared, the Hardys decided that one of them should go to Red Butte to investigate.

âIâll go,â Chet said. âAs long as you guys need help, Iâll stick around for a while.â

He mounted his horse like a bear cub trying to straddle a split-rail fence. After he had ridden off, Frank and Joe saddled their mounts for the ride to Sheriff Paulâs ranch. They hid their camping equipment in a rocky depression, covering it with brushwood, then set out.

It was quite a long ride to the ranch, but finally they reached it. Picketing their horses, they knocked on the back door, which immediately was opened by a trim, middle-aged woman. When the boys introduced themselves, she asked them in.

âWe have a few worries weâd like to talk over with the sheriff,â Joe said.

âMy husband isnât here,â Mrs. Paul replied. âAnd I have a few worries too. He hasnât been home for three days.â

âThree days? Is that unusual?â Frank asked.

âHe got a phone call and told me there was trouble about some rangers. I didnât get the details, because he rode off in a great hurry.â

Joe gave his brother a sidelong look. Rangers ! Could it be the same three men who had ordered Frank, Cap, and him away from the swamp? Frank caught his brotherâs glance and nodded in reply.

âI guess weâd better leave a note for the sheriff,â Frank told Mrs. Paul, who promised to give it to him as soon as he returned.

âMaybe weâd better go back to where we hid our supplies and not go to the Sanderson ranch just now,â Frank told Joe after they had finished the lunch graciously offered by the sheriffâs wife.

The boys headed back toward camp. When they were still some distance from it, Frank, hearing voices, reined in suddenly. Dismounting, he and Joe walked forward cautiously.

âChet! Cap!â Frank exclaimed.

Cap explained that he and Chet had met shortly after the stout boy had left for Red Butte. Cap, having heard about Chetâs arrival and departure from a restaurant owner, had started back but had lost his way.

âIâI like it better here now,â Chet said. âI think Iâll stay till you all go. With Cap here, there are four of us. Just let Willie the Penman dare to show up!â

The tension relieved, they all laughed and set about preparing supper,

As night fell and there still was no sign of the rangers, Frank said, âLetâs sneak back and do some more digging.â

Armed with flashlights and tools, the four carefully made their way down to the fossil deposit. Chet was impressed, and wanted to see more of the camel. However, he soon tired of the digging.

âWhatâs the matter, Chet?â Joe asked. âBreak your shovel?â

Chet grunted and went to work. It was becoming evident that the fossil they were excavating was an enormous one.

âI believe we have a perfect specimen,â Cap said enthusiastically.

Chet found plenty of excuses to rest from his tabors. Only the sarcastic remarks of his friends kept him digging in the spot designated to him. He had not been at it long when he unearthed a half-rotted board.

âHuh,â he said, âall I can do is find clam fossils in Bayport and old billboards out here.â

Frank looked up suddenly. âBillboards? Where?â

âHere,â Chet said, beaming his light on the rotten piece of wood. âIt has letters on it. E R S. What does that mean?â

âCould be part of the name Sanderson,â Joe said.

âPerhaps an old prospector left it here,â Cap volunteered.

Frank snapped his fingers. âI have it!â he cried. âWait here. Iâll be back in a second.â

Without explaining why, he dashed off in the darkness.

âI think he ate some locoweed,â Chet remarked, leaning over his shovel and heaving a sigh.

The words were hardly off his lips when a shriek of terror sounded in the night.

Was Frank in trouble?

CHAPTER XI

Underground Snare

CATAPULTING himself out of the pit, Joe dashed down the slope in the direction Frank had taken. Chet and Cap hurried after him. With their flashlights stabbing the blackness, they finally reached the edge of the swamp.

Just then a flashlight beam was turned on Joe and a familiar voice called, âWhatâs going on? You guys sound like a stampede of water buffalo.â

âFrank! Was that you who yelled?â

âNo. I thought it was one of you.â

âMust have been a wildcat,â Cap said. âThey sometimes sound like humans.â

âSay, Frank, where were you going in such a rush?â Chet asked.

âTo get that sign on the tree. I have an idea about it.â

With the others following, he pushed through the dark swamp to the gnarled willow tree.

Frank pointed out the dangling sign to Chet. Then he yanked the weathered old board loose.

âI want to compare this with the piece of wood you found, Chet,â he said.

As they struggled back up the hill to the pit, Chet puffed and heaved. âYou sureâmake things âhard,â he said.

Joe was the first to notice that something was amiss at the pit.

âHey! I left my shovel right here. Whereâd it go?â

âEverything is gone!â cried Cap.

âThe board too,â Frank said. âWeâve been robbed!â

âThat cry was just a trick to get us away from here,â Cap declared. âSomebody wanted our tools. Put out your lights, boys. Thereâs no sense making targets of ourselves.â

The four stood motionless in the darkness. Frank broke the silence by whispering that it would be hopeless to try finding the thief in the darkness. The logical move was to return to their campsite as secretly as possible.

By this time all of them except Chet knew the route well enough to find it in the dark. Chet stumbled along between Frank and Joe. Reaching camp, they crawled into their sleeping bags.

âNow tell us about the sign, Frank,â Chet whispered.

âI was going to try fitting the two pieces together. I think originally it was all one sign.â

âBut that would mean it doesnât refer to wildcats at all,â Chet pointed out.

âRight! It would read, âHere lie the bodies of twenty wildcattersâ!â

âWildcatters has two tâs,â Joe reminded him.

âThe second t could have been right on the break,â Frank explained, âand easily have rotted away.â

Chet still did not see the real significance. âWhatâs the difference whether there were twenty wildcats or twenty wildcat hunters here?â

Cap spoke up. âA wildcatter, Chet, isnât an animal hunter. Heâs a man who hunts for oil-well locations.â

âOil prospectors!â Chet whistled. âYou mean there might be oil here?â

Cap said that was quite possible, and then Joe exclaimed, âThose rusty pipes we found could have been part of some drilling equipment! And that skeleton in the cave might have been another one of the wildcatters!â

âSk-skeleton!â Chet quavered.

âOh, we didnât tell you about our Mr. Bones!â Joe laughed. âWait till you see him. Heâs out of this world.â

Chet crawled deeper into his sleeping bag and was silent.

âSeriously,â Frank said a moment later, âI wonder what really happened to those wildcatters, and when.â

âIâve been mulling that over myself,â said Cap, âand Iâve about decided that it couldnât have been too long ago.â

âI think youâre right,â said Frank.

âWell, I feel we can be certain,â Cap said, âthat there still may be a few men living who learned about the possibility of oil below the swamp from some of those wildcatters. Thatâs why theyâre trying to run us out of here.â

Frank remarked that a certain George Moffet seemed to fit right into this theory. No doubt he was trying to get Mrs. Sandersonâs property.

âIs there any way of telling where there might be oil except by drilling?â Chet asked Cap.

âYes, indeed,â the teacher replied. âIn certain periods in prehistoric times far more oil deposits were formed than in others. If I could locate some fossils from one of those periods, Iâd know weâve made the right guess about the situation here. Incidentally, every big oil company today employs a paleontologist for this kind of exploration.â

âIf weâre going to do any more digging,â Chet spoke up, âweâll have to buy some more tools.â

âJoe and I might get them in Red Butte after we see Dad,â Frank suggested. âTomorrow night we plan to meet him at Spur Gulch, Cap,â the boy added, and told him about Chetâs message.

Bailey volunteered that he and Chet buy the tools. They would stop at the Sanderson ranch and tell Harry and his mother their suspicions.

Next morning, an hour after sunup, Frank and Joe set off in an easterly direction, while the others went northwest.

âIâd like to look around that cave once more before we leave,â Cap said when they reached the ledge. âBesides examining those pipes again, we may find other clues to prove weâre on the trail of the old wildcatters or of some new ones.â

Chet was reluctant, but on the other hand, he didnât want the teacher to think he lacked courage.

âOkay, Cap. Lead the way!â

When they reached the narrow opening in the rocks, Chet glibly offered to remain at the cave entrance to âguard the horses.â Cap grinned as he dismounted.

âIf thereâs trouble,â the teacher said, âweâre better off together than split up.â

âYouâve talked me into it,â Chet replied solemnly.

Flashlight in hand, Cap stalked ahead of him down the incline to the cave entrance below the ledge. At the end of the passage, where it broadened out into the wider portion of the cave, Baileyâs light flickered.

âBatteryâs getting low,â he muttered to himself.

As Chet beamed his own light around, Cap entered the inner part of the cave. Stepping past the skeleton, barely discernible in the dim light, the teacher bent to pick up a rusted section of pipe. As he did, a faint sound in a recess of the rock wall made him straighten up.

âThat you, Chet?â

âWhat did you say?â Chet boomed from the passageway.

In sudden alarm Bailey swung his fading flashlight toward the wall. It picked up a dark figure crouching in the gloom.

âDonât move!â came a whispered command.

At the same moment, an arm snaked around his chest like a hoop of iron, pinioning his arms to his sides. With a clatter, Capâs flashlight dropped to the rock floor.

âChet!â he gasped. âGet help! Hurry!â

âShut up!â his attacker hissed.

The arm tightened its grip, choking off any further warning. As Cap struggled, another man rapped him sharply on the side of the head with the butt end of his gun. The science teacher crumpled to the floor.

âThatâll take care of him for a while!â the gruff voice muttered in the darkness. âNow letâs get the other one.â

But Chet, having heard Capâs desperate plea for help, had made his decision. Even though he was scared, Chet would never run out on a friend in distress.

He had recently learned some elementary judo. As a flashlight suddenly beamed in the passageway, Chet poised himself. Seconds later a man of medium height emerged from the inner cave.

As Chet had been taught, he let out a blood-curdling scream and shouted some unintelligible gibberish. His amazed adversary stopped in his tracks. The boy backed away a few inches. If he could keep this up until he reached the entranceâ

The man, though, was not to be fooled a second time. He lunged savagely at Chet. Instantly Chet grabbed his outstretched arms and pulled his attacker sharply forward. Off balance, the man stumbled toward him.

With split-second timing, Chet brought his knee up sharply against the manâs chin. He went down like a sack of lead sinkers.

Not knowing there was a second enemy, Chet relaxed. Suddenly his hands were locked behind him in a firm grip. He tried to break free, but the attacker twisted his arms painfully.

Resistance was futile.

CHAPTER XII

Ambush

WHILE Chet was struggling with his new enemy, the man he had knocked down began slowly to get to his feet. Holding his jaw, he shone a big flashlight on the boy and glowered.

âWise guy, eh? Break his arm, boss.â

âCan the cracks! Get on with this job!â

The injured manâs companion collared Chet and shoved him deeper into the cavern, where the other fellow stuck a candle into a crevice and lighted it.

In the eerie glow Chet saw Cap lying prone on the ground. Then, for the first time, he got a good look at the second assailant, a small, wiry man wearing a badly fitting green uniform and holding a short rifle.

As Chet stared, Cap came to and staggered to his feet.

âYouâre the rangers who ordered us out of this area!â he charged.

âVery clever!â the scrawny man said sarcastically. âBut since you werenât smart enough to take a friendly warning, weâre going to teach you a lesson!â

âListen here,â Cap retorted angrily, âI demand that this boy and I be treated according to law. You have no right to hold us without valid complaint.â

âNo? Well, weâre taking the right.â

âYou canât get away with this!â Chet said hotly. âWe know who you are, and we know what youâre after! Youâre impostors, and youâre trying to steal Mrs. Sandersonâs land!â

âAnd you,â Cap added, pointing at the wiry man, âyouâre Willie the Penman!â

The other man looked startled. âThey know weâreââ

âShut up!â the small fellow ordered. He turned to Cap and Chet. âYou donât know what youâre talking about. If you have any sense at all, youâll keep your mouths shut.â He turned back to his companion. âGive me the wire.â

The captives were led deeper underground, back into the dim recesses of the cave. Then the men, using lengths of tough copper wire, tied their prisonersâ hands behind their backs and bound their ankles.

âAre we being kidnapped?â

The little man said with an ugly laugh,â I wouldnât call it that. Weâre not taking you anywhere. Youâre just going to lie right here in this cave and have a good rest.â

âYeah, and when we get around to it,â his henchman added, âweâll send the sheriff to pick you up.â

With that, the two men left the cave. When the sound of their footsteps had died away in the gloomy vault, Chet spoke up. âDo you think they really will send the sheriff to get us?â

âI wouldnât count on it,â Cap replied. âI canât picture those two criminals helping the law.â

âDo you suppose Frank and Joe will ever find us?â Chet quavered.

Meanwhile, the Hardys had altered their plans. Since they did not have to meet their father until midnight, they had decided to ride first to Sheriff Paulâs and find out about the âranger trouble.â

Upon reaching the Paul ranch, the boys dismounted and knocked on the front door. To their amazement, it swung wide open under Frankâs touch,

Joe called out, but there was no reply. He peered into the neat living room.

âThe place is deserted and the note we left is still on the table!â

âThatâs funny,â Frank remarked. âMrs. Paul must have gone off soon after we did.â

âI hope nothingâs happened to her,â Joe said apprehensively.

The boys circled the house, but there was no sign of the sheriffâs wife. Nor was she in the barn or any of the other ranch buildings. The boys were more mystified than ever.

âLetâs go back to the house,â Frank suggested.

In the kitchen they saw unwashed dishes on the sinkâa startling contrast to the spick-and-span condition of the house. Near the door was a basket of clothes. On a hunch, Frank felt them.

âTheyâre still damp, Joe. That means Mrs. Paul was interrupted in her work. She must have left here in a hurry. Letâs check the corral.â

Joe, first to reach it, called out, âLook at these fresh hoofprints. Several riders were here.â

Frank knelt down. âThree sets come up to the gate, then four go away. The question is, Did Mrs. Paul go with the others, or leave later?â

Carefully checking the trail and the turnoff into the ranch, the boys discovered that one set of hoofprints were headed in another direction.

âShe might have ridden off to warn somebody about her visitors,â Joe said, âprobably her husband. But why didnât she use her radiotelephone? I noticed one in the living room.â

Hurrying back to the house, Frank examined the set. âThe sheriff no doubt uses it to contact police headquarters at Red Butte. Iâll do the same.â

He switched on the set and waited for it to warm up. However, no hum came from the loudspeaker. He pressed the microphone button.

âThatâs funny, Joe. This set doesnât seem to be putting out at all.â

Frank tried again, but the output dial remained at zero. Turning off the set, Joe unsnapped the cover slides, and removed the top.

âNo wonder!â he exclaimed. âA tube is missing!â

âThatâs proof enough for me,â Frank cried. âThose visitors were here for no good reason.â

âWeâd better ride to Red Butte as fast as we can and report the whole situation,â Frank said grimly.

âRight,â Joe agreed. âThen later we can hop a train from there to Spur Gulch.â

Hurrying outside, the Hardys sprang into their saddles and galloped off. At this rapid pace, they quickly covered a mile. Then they were forced to slow down because the trail had entered a rocky valley.

As they proceeded, the valley became a narrow pass walled in by steep rock formations on either side.

âI guess itâll have to be Indian file now!â Frank said, cantering in front of his brother. As they neared the end of the pass, he suddenly reined in.

âWhatâs up?â Joe asked, almost colliding with Frankâs mount.

Frank did not answer, but from up ahead, Joe heard a gruff voice shout:

âHold it!â

A man in cowboy attire, astride a pony, blocked the exit to the pass. The boys couldnât see what he looked like, because of the dirty blue kerchief tied over the lower part of his face and a ten-gallon hat pulled low on his forehead.

âI see youâre packing a gun!â he remarked, looking at the weapon Frank carried in a holster.

âYes. Protection against wild animals.â

The cowboy gave a sarcastic laugh. Then he pressed his horse up beside Frankâs mount and tried to make a quick grab for the boyâs gun.

But Frank was alert. As the strangerâs arm shot out toward his holster, the boy stood up in his stirrups and brought his fist down hard on the manâs wrist.

Frankâs gun clattered to the ground. His horse reared, making the strangerâs pony shy too, and the masked man lost his seat. His own weapon was dislodged and flew several feet away as he hit the sand.

âCome on, Joe!â Frank cried. âHelp me tie this guy up, quick!â

As Joe slid off his mount, he grabbed the rope from the pommel of his saddle and hurried to assist his brother. It was dangerous business, maneuvering in the narrow pass among the excited, rearing animals.

Scrambling to his feet, Frankâs assailant began to back out of the pass. He reached for his gun. Realizing it was gone, he turned tail and started to run.

âHelp!â he shouted.

Frank and Joe ran to intercept him. Joe tackled the man about the knees and dragged him to the ground. Frank, following up his move as fast as he could, seized the manâs flailing arms.

But even as he did, Frank spotted a quick flash of movement to his left.

âWatch out, Joe!â he yelled. âThere are more of them!â

Two masked men now sprang forward. As the Hardys whirled to meet this new threat, the ambushers charged!

CHAPTER XIII

An Icy Dungeon

âGET âem!â

Though completely helpless under the doublebarreled Hardy attack, the mysterious enemy managed to shout orders to his oncoming aides.

Frank side-stepped a fist from one of the other masked men and landed a hard blow on the attackerâs chest. As Joe ducked a charge from the third ambusher, their fallen leader arose and dived at the boy from behind.

Thrown off balance, Joe was an easy target for his two opponents and went down like a tenpin. Against three, Frank stood no chance at all, and was quickly pulled to the ground.

Within a matter of minutes, the boys were bound and gagged, then heaved crosswise onto the saddles of their horses.

âThese men must be some of Willieâs gang,â thought Frank as the horse started to move. âNow what?â

There was no indication from the cowboys as to where they were taking the Hardys. Except for a terse command now and then by their leader, the men guided them silently on a grueling ride through the rough country. Two of their captors rode ahead, the other at the rear.

âWhy have they kidnapped us?â Joeâs mind was in a whirl. âHow did they know where to wait? They must have had us under surveillance all along!â

One hour went by, two, three. Frank and Joe had been in many a tight spot, but none had ever seemed so hopeless as this one. Each jog of horse and saddle against stomach and ribs knocked the breath from their bodies. The boys realized they were becoming so exhausted and sore that even if they could manage to struggle free, they would not be able to walk.

Worst of all, they realized that they now would have no chance of meeting their father at Spur Gulch.

Hours later Frank and Joe heard the whistle of a train and shortly afterward they were approaching the railroad line. As close as Frank could figure, they were intersecting the railroad right-of-way much farther west than Spur Gulch.

From behind a massive rock beside the shimmering tracks came the sound of a horseâs whinny. The man in the lead halted. He thrust two fingers in his mouth and gave a shrill whistle. Immediately another masked man rode into view.

âSo you got the meddling kids!â he boomed. âGreat work! Weâll get rid of âem right away!â

âWhatâs your plan?â asked one of the others.

âTossâem on the rails!â

From their awkward positions, lying across their saddles, the boys studied the newcomer. He was a big, heavy-set fellow. Could this be the convict Jesse Turk, who had so cleverly escaped from Delmore Prison?

The other man who was as tall, but not as heavy as the newcomer, shook his head. âYou want us all sent up for lifeâjust when we can get clear?â he shot back. âIâve got an idea how to put these smart-alecky kids out of the way and make it look like an accident.â

âHow?â

âThe freight thatâs coming through here from the west at ten-thirty is hauling refrigerator cars. Itâs due in an hour. Weâll put these kids on ice!â

âHey, that sounds like a good deal. I go for that.â And the others readily agreed.

The heavy-set fellow spoke up again. âBreak out some chow. Weâll give these boys their last meal.â

As Frankâs and Joeâs horses were led away from the main party, their guard drew a bowie knife.

âTossâem on the train rails!â

Dismounting, he slashed the ropes that bound Frankâs wrists and ankles.

âGet off and untie your brother,â he ordered roughly. âAnd no tricks! Hear me?â

Frank was only too glad to obey. He unfastened the handkerchief that had been stuffed into his mouth, and hobbled over to where Joe still lay across his mount. While seeming to struggle with the knotted bonds, he whispered furtively:

âJoe, Iâm sure the newcomer and the other big man are the ones we captured at Green Sand Lake. Flint and Turk!â

âI think youâre right. But weâre not going to sit here and let them get away with this, are we?â

âIâll say not! Dad wants these crooks, and weâll get âem. Soon as the kinks are out of us, Iâll give you the signal and weâll put up a fight.â

âCut it out!â their guard shouted. âNo talking!â

By the time Joe was untied, supper was brought to them by one of the masked men. Seated with a rifle across his knees, he watched the captives eat while the other guard walked off for his dinner. The boys were hungry enough for a good meal, even though their minds were occupied by the grave danger facing them.

As Joe set down the tin can from which he had been drinking water, he whispered, âFrank, how come they left only one guard over us? Where are the rest of them?â

Frank smiled grimly. âThe others wanted to eat, I guess, and you canât eat with a bandanna over your mouth! They donât want us to see who they are.â

Hearing their murmuring, the guard turned. âAll right, you wise guys, one last warning. You want your gags back on? One more sound outta you, andââ Suddenly he stopped, cocked his head, and let out a loud roar. âWell, we donât have to worry about you much longer. Here comes the freight.â

As the train drew nearer, the rest of the gang appeared and surrounded the captives.

âGet ready for your last mile,â the brawny man said sardonically. âCurtains for two detectivesâand one to go!â

The boys winced. By âone to goâ the scoundrel could not mean anyone but their father. They must know he was in the vicinity of Spur Gulchl He might even have been captured already!

Crouching behind a low outcropping of rock along the tracks, the men forced the boys down with them. The railroad ran up a slight grade at this point, and the heavy Diesels struggled and churned as they reached the incline. Slowly the twin locomotives neared the hidden group.

âThisâll be a snap,â one of the men said confidently. âIâll break the seal on a cooler first, and thenââ

Suddenly Frank sprang up. âAt âem, Joe!â

âHey, whatâsâ?â

The manâs cry was cut off abruptly as Joeâs fist crashed into his mouth. Blood spurted from his lips, and he gave a yell of surprise and pain.

Shoving one of their abductors backward into another and sending both sprawling, Frank turned and butted headfirst into a third.

As they battled against the heavy odds, the boys shouted at the top of their voices for help. But their cries were lost in the thunder of the Diesels as the big engines roared past. No one on the train had seen the ruckus, and now no one could hear it!

Although the Hardys fought furiously, they were outnumbered by their enemies. Subdued, they were held this time in steellike grips. The man who had proposed the refrigerator cars had ridden down the tracks, watching for a âcooler.â

As one passed, he urged his horse alongside. The animal kept pace with the moving car while its rider leaned over toward the door. Skillfully he broke the metal seal and slid open one of the heavy insulated doors.

The open car drew abreast. Frank and Joe were seized tightly, then heaved up and into the yawning opening of the refrigerator car. The heavy door slammed shut, and they could hear the bar fall into place on the outside.

Joe was first to speak. âFrank! Weâre locked in,â he said hoarsely. âWeâll freeze!â

His brother sat up and nodded. âEasy, Joe. Weâll have to stay calm if we expect to get out of this alive.â

Groggy, they stood up and tried to keep their balance in the pitch-black, chilly car. The only sound was the clackety-clack of the wheels. Frank took a small flashlight from his pocket and looked around. Their prison was filled with crates of West Coast lettuce.

Climbing up and over them, Frank presently came to the front wall of the car. It was damp and freezing cold against his hand.

âJoe! I just remembered something,â he said hopefully. âWeâre lucky. This is an old-type car. In the new nitrogen refrigerator units weâd be goners for sure. They have practically no oxygen.â

âYouâre right. This oldie has ice compartments at each end. Bunkers.â

âExactly. The bunkers open into this section near the roof, so the cold air can circulate. What about it?â

âThatâs our way out. Each bunker has a hatch in the roof, where ice is put in.â

By the dim beam of the pocket flashlight, they could see that the open parts of the bunkers were covered by wire.

âIf we can only cut through that!â Frank said.

âHere.â Joe pulled a knife from a pocket in his dungarees.

Climbing up on the stacked lettuce crates, Frank began hacking away at the wire screen. With only the small penknife, it took time, but finally he made a hole large enough to crawl through. Perched atop a slippery cake of ice, he reached up for the hatch.

It was tightly locked.

âNo luck,â he called down in disappointment.

Descending to the floor of the car, he added, âWe have only one more chanceâthe other hatch.â

âLet me try this time,â Joe suggested.

âOkay. Maybe youâll be luckier than I was.â With teeth chattering, Joe sawed away at the wire mesh of the other bunker and worked his way in on top of the ice. Anxiously he glanced up at the hatch. A thin sliver of light showed along one edge.

âFrank!â he shouted exultantly. âThis one isnât locked!â

Quickly Joe leaned down over the edge of the bunker and helped Frank climb up into the ice chamber. Together, they pushed at the hatch cover, but it didnât budge.

âJoe! All your might!â Frank urged. âThis is our only chance!â

âMy hands are so numb I canât even feel the hatch.â

âWeâve got to make it!â Frank gasped.

CHAPTER XIV

Thievesâ Camp

BRACING their shoulders and arms beneath the hatch of the refrigerator car, Frank and Joe gave one more mighty heave. This time they forced the cover upward and held it against the rushing wind as they scrambled out.

A blast of air nearly threw them off balance. But it was warm, and felt wonderful against their frigid skin.

âDuck down!â Frank yelled. âLess wind resistance.â

The train had topped a long grade, and was speeding now to make up for time lost on the hill. The boys swayed as the freight rounded a long curve.

Frank glanced back through the gathering dust to see if he could spot any familiar landmarks. Checking his watch, he surmised they must have traveled past Spur Gulch.

âHey!â Joe cried out. âWeâre slowing down!â

âGood!â returned Frank. âI think our best bet is to hop off and walk back to the Gulch.â

Amid the rattle and banging of couplings, the long freight train jarred to a stop.

âOut on the sand!â yelled Joe as he eased down on the smooth surface. A hundred yards down the track Frank followed.

âNow,â Frank said, âwe have a good hike ahead of us back to Spur Gulch. Itâs nearly time for our date with Dad.â

They had hardly hit their stride along the ties when Frank pulled up short.

âLook over there, Joe. In that patch of woods.â

The orange-and-red light of a small campfire flickered through a thick grove of trees.

âShould we take time to see whoâs there?â Joe asked. âAfter all, weâre late now. That campfire may belong to a gang of hobos.â

âOn the other hand,â Frank reasoned, âDad might be there.â

Frankâs argument convinced his brother, and the two boys left the right-of-way.

Careful not to make any noise, the Hardys advanced among the trees. At the far edge of the grove in which the fire was located they paused in the underbrush and peered ahead.

A dozen men were huddled around the fire. Two were eating. The others appeared to have finished their meal and were warming themselves near the blaze.

In the low buzz of conversation someone occasionally would make a wisecrack that provoked a chorus of rough laughter. Presently a deep voice which was raised above the rest gave the Hardys a chance to learn the subject of the menâs conversation.

âWell, the boss and his new friendâll be here soon,â the man rumbled. âThen the fireworksâll start!â

âWe canât wait for them much longer,â another voice announced impatiently. âNumber 68âs due here in a little while.â

âThese men must be train robbers!â Frank whispered. âTheyâre waiting to wreck Number 68 on the tracks right over there!â

âThen maybe weâre not too late,â Joe said hopefully. âDadâs probably around here somewhere. Letâs get closer to these guys. Maybe we can hear exactly what theyâre up to.â

The boys had crawled forward several feet when Frank gripped his brotherâs arm, pulling him to a stop. With his other hand cupped around Joeâs ear, he whispered:

âIt just occurred to meâthat fellow mentioned the boss and his new friend. Do you think he could have meant Flint and Turk?â

Edging forward on their knees and elbows, the boys tried to get a better look at the faces of the men in the flickering firelight. One of them, his back to the Hardys, addressed the others.

âCan ya imagine a coupla high school kids holdinâ up a deal like this. Well, we donât have to worry about them any longer. Flint said heâd take care of âem before he got here.â

Flint! The boysâ deduction had been correct!

âAt least,â Frank told himself elatedly, âweâre on the right track now.â

âMe, Iâm gettinâ tired of waitinâ,â one of the men grumbled. âThe sooner we get at this job, the better. I want to put the grab on those pipes and drills and then blow outta here.â

âSure, Hank,â another agreed. âThe sooner we get hold of that stuff, the quicker we can set up the digginâ.â

âFlint said Number 68âs got three cars loaded with the last word in oil rigs,â Hank went on. âWeâll be rollinâ in dough in a few weeks, and by that time itâll all be on the level.â

Joe prodded Frank and the older boy knew what he was thinking. The stolen rig was to be set up in Wildcat Swamp after the land had been taken from Mrs. Sanderson!

âNo wonder those phony rangers invented that government order for everyone to move out,â Frank whispered.

Joe was about to speak when a sudden crackling in the woods startled him.

âToo late to run!â Frank whispered. âLie flat!â

Face down in the undergrowth, they hugged the dry ground. The sound of heavy footsteps grew nearer. The newcomers passed the boys and approached the campfire. Conversation died abruptly. Frank and Joe looked up momentarily, to see one of the men jump up, draw his pistol, and hurry away.

âWhoâs there?â he called, advancing to only a few feet from where the boys lay hidden.

Frank and Joe hardly dared to breathe until the challengerâs attention was diverted by the two new arrivals who stepped into the firelight.

âWhatâs the matter with you, Sam? Jumpy tonight?â one of them asked in a low, controlled voice. Better dressed than any of the others, he presented an almost distinguished appearance.

The man with him was big and broad-shoul dered. Even from where the Hardys lay squinting through the brush, they could see him frowning darkly at the others who now clustered around.

Now Frank and Joe were absolutely sure. The men were indeed the Green Sand prisonersânow without their cowboy disguise and masks!

The boys listened tensely.

âOkay, Flint,â replied Sam, ramming his pistol back into its holster. âItâs this waiting that gets on my nerves.â Then, turning to the others, he added, âMeet your boss, men.â

Flint was received enthusiastically. All the gang were eager to get their new job under way and the arrival of the boss meant time for action.

Leading his companion into the center of the group, Flint said, âMen, I want all of you to meet an old pal of mineâJesse Turk. Heâs going to be in on this caper with us.â

âThatâs okay by me,â Hank said approvingly. âThereâs gonna be enough dough for everybody.â

âRight!â Flint added. âThis job is a lead-pipe cinch. We had a little trouble getting rid of those Hardys. And then that fool fossil hunter.â

âWhat happened to him?â Hank asked.

âHe and the fat kid with him are tied up and hidden away in a caveâwithout food and water.â

Involuntarily, the Hardys winced at the reference to their friendsâ plight. Joe, in sudden anger, started to scramble to his knees, but Frank laid a firm hand on his arm.

âTake it easy, Joe. We can help Cap and Chet more by learning all we can here.â

Though Frank had restrained him quickly, Joeâs sudden movement had been heard. A tall, hard-bitten member of the gang sprang to his feet.

âBoss, what was that over there? I swear I heard something move.â

There was an ominous silence as the others listened, too. The wind had died down and not a leaf stirred. Suddenly the still night rang with a rasping laugh. It came from Turk, and his harsh amusement echoed through the woods. The rest stared at him.

âFlint, I thought you said you had men here!â he said bitingly. âThese guys are nothing but a bunch of scared rabbits!â

There was an immediate and angry muttering among the group of outlaws. Before it could develop into a fight, Flint stepped forward.

âAll right, knock it off,â he ordered briskly. âYou guys have nothing to worry about. Those snooping Hardy kids have frozen to death in a refrigerator car, and their old man is next.â

âYou got him too?â Hank smirked.

âNo, but we heard where he is. This jobâll be a cinch now.â

His authoritative demeanor having eased the tension, Flint drew Turk and Hank aside in a private conversation, while the others began talking of the robbery plans. Taking advantage of the general chatter, Frank nudged Joe.

âBack out of here,â he proposed in a whisper.

Joe nodded and began inching his way backward through the brush. They had to get awayâhad to get to Spur Gulch, find their father, and warn him.

They had moved about half the distance to the edge of the grove when they heard Flint giving more orders.

âEnough talk, men! Time to get moving. Weâve got a job to do before we can pull the holdup.â

To the boysâ horror, the men picked up flashlights and began to tramp through the trees right in their direction.

âTheyâll spot us this time,â Joe groaned. âHow are we going to hide from all of them?â

Frankâs quick mind hit upon an idea. âHurry! Up a tree!â

Rapidly, before the beams of the flashlights could reach them, he and Joe picked out two sturdy pine trees with low-hanging branches and shinned up into their thick foliage.

Seconds later the men pushed past beneath them and moved out of earshot.

âThat was close,â Joe muttered as they climbed down. âNow what?â

âItâs better this way,â Frank told him. âNow we can trail them.â

The boys followed the gang, keeping well concealed. It was hard going without lights in the dark woods, and their pace was slow compared to the menâs.

Finally they saw the gang break out of the woods near the summit of the hill on which the boys had jumped off the freight car. Beyond, the roadbed curved and descended in a long horseshoe.

âLetâs go over there and watch,â Frank said, pointing to a cluster of tall bushes down the tracks from where the men had emerged.

Halfway around the curve of the tracks, the outlaws disappeared into the trees again. A moment later, when Joe was about to start after them, they reappeared, their flashlights bobbing as if they were carrying something.

âWhat have they got there?â Joe whispered.

âLooks to me like old railroad ties,â Frank answered. âBut what on earthâ?â

His unfinished query was answered immediately as the men heaved the great chunks of wood onto the tracks and set them afire.

A bright flame licked at the tinder-dry wood, and in no time it had grown into a crackling blaze.

âFrank, we must warn the engineer!â Joe cried.

The boys started in the direction the freight would be coming.

But at that moment Flint stepped into their path and shouted:

âItâs burning fine, men. Here comes that rattler. To your jobs!â

Splitting into small groups, his henchmen disappeared into the night. Flint hurried off down the tracks toward the freight.

âNowâs our chance,â Joe said. âWe may be caught, but we ought to make a try.â

âWeâll certainly be caught if we go that way,â Frank objected. âLetâs see if we can push those burning logs away so the train wonât have to stop.â

CHAPTER XV

The Wreck

DASHING uphill as fast as their legs would carry them, the Hardys sped toward the pile of burning ties. Reaching the spot, they found the center a roaring blaze, the heat intense.

Nevertheless, the two boys tugged frantically at the end of one of the heavy ties. At first it would not budge, and the Hardysâ faces were scorched before they managed to drag the heavy piece of wood away from the pyre. Its removal caused the others to collapse, sending sparks in every direction.

âItâs no use!â Frank panted, beating off the sparks that singed his shirt. âWe couldnât clear this away in time.â

Their faces and arms smarting, and their eyes bloodshot, they were forced to move back.

âWeâll have to try the other plan,â Joe urged. âCome on!â

Frank was dubious of its success, but he fol lowed Joe. They hurried forward, jumping from tie to tie.

âI hope none of that gangâs watching,â Frank said. âIf they see us, itâs curtains.â

Aided by the downgrade, the boys put a quarter mile between them and the fire before they saw the bright beam of the freight trainâs headlight. As the long train bore down on them with a roar, the Hardys took a determined stance in the middle of the track, waving their arms furiously. A second later the hoarse, warning honk of the Dieselâs horn split the night with staccato blasts.

Still the boys held their position. The Dieselâs air brakes suddenly were jammed on with a shriek, and the heavy freight ground to a stop. As the Hardys rushed toward the locomotive, the engineer leaned from the window.

âAre you kids crazy?â he bellowed. âYou could have been killed! Whatâs the idea?â

âThereâs danger ahead!â Joe blurted.

âTrain robbers!â Frank added.

In a space of a few seconds, the Hardys impressed upon the engineer the necessity for speedy action. Turning, the man seized the induction telephone to the caboose, and frantically tried again and again to contact the men there.

âThis is dead!â he cried. âThereâs no answer!â

Just then, from the other side of the big locomotive, came a rough command:

âDrop that phone and put up your hands!â

The engineerâs eyes widened in panic. Letting the instrument fall to the floor, he raised his hands, at the same time trying to nod to the boys to warn them.

There was nothing for Frank and Joe to do but to slip quietly into the brush along the tracks. From this cover, they peered up into the cab.

Two masked men were climbing into the compartment from the other side of the train, holding at gunpoint both the engineer and his fireman. Up the track, other members of the gang were using long hooks to remove the smoldering, red-hot ties.

âIf we cut through the woods, we can warn the crew in the caboose ourselves!â Frank urged.

Stumbling blindly through the darkness on the inside of the horseshoe curve, the boys made their way toward the end of the long freight. They tripped over fallen logs, and whiplike branches cut their faces.

âThere are the lights of the caboose,â Frank gasped. âKeep going!â

Guided by the lights, they broke out of the woods and clambered up a short slope. Joe grabbed for the railing and scrambled up the iron steps. Frank was right behind him. They had barely reached the platform on the tail end of the car when the train gave a lurch.

âWeâre moving!â Joe yelled.

The next instant a voice, which was strangely familiar, shouted: âJump!â

The command carried so much authority that the boys obeyed instinctively. Leaping backward, they somersaulted down the cinder-packed embankment. Unhurt, they sprang quickly to their feet.

âThe end of the train has broken loose!â Joe shouted.

The caboose and three big flatcars adjoining it had cut free and were rolling downgrade. The rest of the freight had started pulling ahead.

While the front section was slowly picking up speed, the four end cars were gathering momentum every second as they took the downhill curve.

âTheyâll derail!â Frank shouted. âThe whole crew in the caboose will be killed!â

Hardly were the words off his lips when there was the sound of crunching steel, accompanied by flying sparks as the cars leaped the tracks.

With a tremendous roar, the cars toppled over the embankment. Their cargo slid off the toppling flatcars, scattering along the wooded right-of-way.

Several minutes passed before the din made by the falling pipes quieted.

The Hardys started running toward the wrecked caboose, fearful of what they would find.

âWe might have been on that!â Joe said.

âWho yelled âJumpâ?â Frank asked.

âSay, Iâd forgotten about that,â Joe answered.

âSh-h-h!â

The whispered warning came from behind them. Wheeling about, the boys saw a dim figure half hidden under a bush. A tall, strongly built man beckoned to them.

âDad!â Frank and Joe exclaimed in unison.

There was no time now to exchange stories. The three raced to the site of the wreck, climbing around scattered pipes and splintered boxes.

âThereâs the caboose!â Joe called. âThe door has been ripped off!â

Quickly all three pushed through the debris to the train crewâs headquarters. Pulling themselves up its splintered sides, they peered down into the twisted, torn wreckage.

âThere isnât anyone in it!â Mr. Hardy exclaimed. âThank goodness you boys heard me and jumped.â

âBut whereâs the crew?â Joe asked. âThe engineer was trying to get someone on the induction phone in his cab.â

âThey probably jumped out to see what was happening when you boys flagged the train,â Mr. Hardy deduced. âThey may have been coming up along the embankment when the last four cars started rolling.â

âIn that case, the crew should be around here somewhere,â Frank said.

âYes, but I doubt very much if they would be a match for such a large gang as this one. Now the question is, Did those cars break loose, or did someone uncouple them?â

âThey were wrecked on purpose,â Frank answered, and told his father all that had happened since the shooting down of the radio aerial balloon; how they had overheard that Flint was boss of the gang; how Cap and Chet were prisoners in a cave; and all because the ex-convicts wanted to drill for oil illegally on Mrs. Sandersonâs land.

âWeâll rescue Chet and Cap as soon as we can,â Mr. Hardy decided. âTheyâll have to hold out awhile. First we must do something about this gang here, and itâs going to be tough without help.â

âAre you alone, Dad?â Joe asked.

âSam Radley is out here working with me, but all our tips pointed to Spur Gulch as the trouble spot. He was bringing a posse to meet me there. But now that youâve told me about the oil drilling, I can see why Flint picked this place. Those three cars contain the materials they need. Thereâs a rough woods road near here over which they can drag the stuff.â

âDad, how come youâre in this spot alone?â asked Frank.

âJack Wayne flew me in. The only level spot on the mountain was about half a mile from here. I planned to walk to Spur Gulch along the tracks.

âOn the way, I came almost face to face with some of this gang, and couldnât get past them. What I have been doing is taking pictures with our infrared camera of any of these thugs I could get close to. Weâll have quite a record ofââ

A shot rang out, then another. A moment later two uniformed trainmen came racing in their direction, followed by two of the robbers. Mr. Hardy, whipping out his own revolver, was about to go to the assistance of the trainmen when six more armed outlaws came into view.

âWeâre outnumbered,â the detective said in disgust. âOur only chance to capture that gang now is by a trick.â

The Hardys hugged the trees to keep from being seen, but even from his hiding place, the detective kept clicking his camera.

âThis is all good evidence,â he whispered grimly. âWhen we get this mob into court, the jury wonât take long to convict every one of them.â

Frank and Joe had no doubt of their fatherâs ability to outwit the gang eventually, but at this moment the situation looked desperate. Besides, all three of them were in danger of being captured.

âKeep under cover,â the detective warned as Joe stepped out. âThis is no time to be discovered.â

The words were hardly out of his mouth when their hiding place became flooded with light!

CHAPTER XVI

The Rough Ride

SIX bright beams of light swept the Hardysâ hiding place from the opposite side of the tracks. As they drew closer, they could make out two low-slung open trucks, each with a powerful spotlight, in addition to glaring headlights.

âGreat crow!â Joe exclaimed. âWhere did they come from?â

âOver the abandoned logging road,â his father replied. âMore of Flintâs smart organization work. Those trucks can carry the pipes and oil-well equipment out of here easily.â

âCanât we do something?â Frank asked desperately as the trucks lurched across the rails and halted alongside the wrecked cars.

âI think so,â his father said coolly. âIâm going to trick Flint and try to capture him.â

The detective turned to his sons. âYou boys take note of whatâs going on here. Wait until the next train passes through. Thatâll be at nine A.M. The robbers will have left long before that. Stop the train and ride to Red Butte. Iâll meet you there at noon.â

The detective pulled out a small bottle. âConcentrated food tablets,â he said, handing them to Frank. âYou may need them.â

After saying good-by to his sons, Mr. Hardy crawled through the bushes until he was in heavy cover. Then he stood up cautiously. Returning to the tracks, he walked upgrade a considerable distance from the scene of the robbery.

When the detective was sure he could not be seen by the men loading the boxes and pipes onto the trucks, he crossed the tracks.

Easing back to the scene slowly, he spotted two figures who stood on a rise, silhouetted against the night sky. Mr. Hardy moved within hearing distance.

âWorked like a charm, Turk,â one of the men said. âI uncoupled the last four cars and clamped the air brake on the forward section, so the rest of the train could move ahead as soon as Pete got the burned ties off the tracks.â

âFlint, youâre a brain. We ought to have this load out of here within an hour.â

With a grim smile on his lips, Mr. Hardy stepped into the open.

âFlint!â he shouted.

The two train robbers whirled around. The shutter of the detectiveâs camera clicked twice. Turk beamed his flashlight as Mr. Hardy ducked.

Flint cursed, whipped a pistol from his shoulder holster, and fired a clip of bullets at the spot where the detective had stood a second before.

âItâs Fenton Hardy!â Flint roared. âTurk, you supervise the men. Lend me your light. Iâm going to get this dick if itâs the last thing I ever do!â

As soon as the detective saw Flint coming after him, he drew back into the wooded area and headed for Jack Wayneâs plane. Mr. Hardy deliberately let Flint catch an occasional glimpse of him, leading the gangleader farther away from his men.

Flintâs rage increased as the detective tormented him with a dangerous game of cops and robbers. Half an hour later Mr. Hardy emerged from the woods into a clearing, in the center of which stood Jack Wayneâs plane. Running toward it, the detective shouted:

âJack! Flintâs right behind me. Cover me while I give him a whiff of the gas gun!â

As a face appeared in the pilotâs window, the detective stopped short. Instead of Jack Wayneâs familiar features, he saw in the moonlight a thin face with a large sharp nose and eyes like black marbles. An unknown enemy was facing him and Flint was only a few steps behind!

Meanwhile, the detectiveâs sons had continued to watch the well-planned and executed theft of the oil-well drilling equipment. The freightâs conductor and brakemen were being kept covered.

In an hour the two trucks were loaded and the cargoes concealed with heavy tarpaulins. Two men climbed into each cab and the others faded into the woods along with their prisoners.

âSo long!â one driver called. âSee you at Wildcat Swamp after we deliver this stuff to Willie and Nick Snide.â

Frank and Joe exchanged glances. No doubt the man meant Willie the Penman. But who was Snide?

The Hardysâ nerves tingled. âFrank, are we going to stand here and do nothing?â Joe cried.

âNo sir. Come on!â Frank muttered. âWeâll ride back to Wildcat Swamp and free Cap and Chet.â

âHow about meeting Dad?â

âWeâll get thereâmaybe just a bit late.â

As the trucks pulled away, the boys ran across the track. Racing down the other side, they found the narrow, overgrown logging road, then began following the second truckâs taillights.

Fortunately the loaded vehicles were forced to crawl along the twisting logging road. Jogging alongside, Joe was able to untie a corner of the tarpaulin and boost himself aboard the load of loose steel pipes. He pulled Frank up after him, and the boys retied the canvas over them. As the truck rolled along through the night, Frank whispered:

âFrom the feel of the grades and turns, weâre still on the logging road.â

âItâs rough going,â Joe replied. âI wish theyâd picked a smoother route.â

With each big lurch and bump, the pipes clanged and slithered into new positions. The boys fought to keep their balance and avoid being pinched between portions of the cargo.

After what seemed hours, the truck groaned to a stop. Another vehicle approached at high speed and roared past, the sound of its whining tires fading in the distance.

âWe must have reached the main highway,â Frank deduced.

A moment later the truck edged onto a smooth pavement.

âThank goodness for this,â Joe whispered.

The driver shifted into high gear, and the vehicle rumbled along smoothly. Despite the boysâ discomfort, the harrowing experiences of the day and night were making them drowsy. After what seemed to be hours, Joe awoke with a start. He reached out and shook his brotherâs arm.

âFrank! Wake up! Weâve stopped!â

Joe found a tiny hole in the canvas and peeked through it.

âWeâre at a diner,â he whispered. âThe driver and his helper are going to the door. The other truck is parked ahead of us.â

Frank drew his penknife and cut a small peep-hole. âTheyâre probably stopping for a cup of coffee,â he whispered. âWhen they get inside, letâs go in the back way and phone the police.

âGet back! Theyâre coming out!â

The driver and his helper, who was fairly young, approached the truck, accompanied by a third man. As they headed toward the back of the vehicle, the boys eased forward and slid between the pipes and some boxes, just as the tarpaulin was lifted, letting in a slit of light.

âWe got it, all right,â said a voice the boys recognized as that of the driver. âThe whole works.â

âWhatâs up there in front?â the man from the diner asked.

The boys held their breath.

âBoxes of drill bits and fittings.â

From the menâs conversation, it became evident that the newcomer owned the diner. As the cover was tied down again, he said:

âI got a report from Flint already.â

âSo quick? Whatâd he say?â

âBuzzed me on his pocket radio. Heâll be along soon. Said to tell you that he and Fliegel captured Fenton Hardy and his pilot.â

The words came like an electric shock to the boys. Flint had turned the tables and captured their father!

âMan, that was fast work!â the driver said with a hoarse laugh. âFlint just told us back at the railroad he had a plan for getting Hardy.â

âWell, he did it. Mustâve done a real job on him, too. Flint said the dick needs a doctor, but he ainât getting one! You get started. Iâll take a look at the other truck.â

Frank and Joe were frantic with worry. Their father was injured and needed help, and here they were, powerless to aid him.

As the truck started along the highway again, Joe said, âFrank, weâd better get off the first chance we have. Weâll find a ranch house and call the police. Weâve got to find Dad!â

âYouâre right.â

The boys watched through the holes in the canvas. But they passed no ranch houses and the truck sped through the night at high speed. The boys heard the driverâs helper say to his companion:

âYou know, I donât trust that flat-nosed Snide. I think heâd double-cross the lot of us in a minute, if he had the chance.â

Joeâs elbow dug into Frankâs side. Flat-nosed! One of the phony rangers had a flat nose!

âBut you gotta remember, Charlie,â the driver was saying, âSnideâs a good oilman. Heâll be useful to have around.â

There was a snort from his companion.

âI donât careâIâd rather do without him. Heâs too ready to go to extremes. He woulda killed one of those kids without battinâ an eye, and I just canât go that far.â

âAw, can it! Anybody gets in our way deserves what he gets.â

There was a growl of disagreement from the younger man, but apparently he could not see much sense in continuing the argument. The men lapsed into silence.

âThat young helper doesnât sound like such a bad sort,â Frank whispered to Joe. âI wonder how he got mixed up with a gang like this.â

They felt the truck slow down and turn off the smooth highway onto a bad road. The wheels alternately crunched over loose stone and slid through soft sand.

It was perilous going. The Hardys were forced to move from behind the crates and crouch on top of the load. As the truck hit a bad bump, the younger man shouted:

âHey, watch it! This ainât no superhighway!â

âCalm down,â the driver said irritably. âItâs only ten miles to the swamp, Charlie.â

âJust the same,â Charlie said, âthere ainât no reason to set a record. We passed the other truck an hour ago.â

The truck lurched over, its right wheels slipping sideways. âWatch that ditch!â

âAw, shut up! You been a pain in the neck ever since we started this job.â

âI donât like whatâs goinâ on. Ifââ

His words were cut off as the big vehicle skidded. The load shifted sharply, sending an avalanche of pipe toward Frank and Joel

CHAPTER XVII

A Friendly Outlaw

âLOOK out, Frank!â The warning shout slipped from Joe involuntarily.

Reaching high, the boys grabbed the cross braces, and pulled themselves up just as the heavy sections of pipe crashed across the floor of the truck.

The big vehicle skidded to the side of the road, shuddering as it hit the soft shoulder, and stalled.

âNow youâve done it,â they heard the helper berate the driver. âIf we get stuck here, the bossâllââ

âShut up!â the angry driver commanded. âDidnât you hear that yell? Somebodyâs in the back of this truck!â

âAw, youâre loco.â

âListen, bud, I heard somethinâ, and Iâm checkinâ up.â

With a mad scramble Frank and Joe slid from under the tarpaulin and landed in the road. Quietly they ducked underneath the truckâs chassis, just as the husky driver swaggered down from the cab.

He walked along the side of the truck to the rear, the boys watching his feet every step of the way. Leaning over the tailboard, he fumbled with the canvas tarpaulin. Joe looked at the manâs legs, so near his own hidden shoulder.

âToo good to miss!â he thought.

Reaching out his arms, he grabbed the back of the driverâs legs and yanked them forward. There was a startled umph as the fellow went crashing to the road. His gun went one way and his flashlight another. Before he could yell to his helper, the two boys were upon him. Joe sent his fist swinging hard to the manâs jaw, and he collapsed without a sound.

Quickly the boys dragged his inert form under the truck. They were not a second too soon.

âWell, did you find anythinâ?â Charlie called as he climbed out of the cab.

Receiving no answer, he stalked to the rear of the vehicle to investigate. Frank set himself to duplicate his brotherâs action. His shoulder hit the man just below the knees, and before Charlie knew what was happening to him, Joe dealt him a knockout blow.

âWhat are we going to do with them?â Joe asked.

âI donât know yet, but weâll have to do something fast. Look!â

Down the road, still a good distance away, two bouncing pinpoints of light became visible. The other truck was catching up with them!

âCome on. Weâll drag these fellows into the tall grass there.â Frank indicated the high growth on the other side of the road, and quickly they tugged the two unconscious men out of sight.

âWeâd better run,â Joe advised.

Frank had another plan. âWe donât want them to stop. Letâs put on their caps and pull âem down. Theyâll hide our faces a little, and maybe we can get by.â

âAll right. You get in the cab. Iâll pretend Iâm tying this canvas, and you wave them on from the window,â Joe suggested.

By this time the beams of the other truckâs headlights were almost upon them. Frank climbed as casually as he could into the cab and sat there with his left hand giving the passing signal. Joe fussed with the canvas on the side of the truck opposite to where the other vehicle would pass.

Those few seconds seemed an eternity to the boys as the second truck rolled up to them, but fortunately it did not slow down. There was a shouted ridicule about âlazy coyotes,â but the driver kept his foot pressed down on the accelerator.

The driver went crashing to the road

The scheme had worked!

âWeâd better get back to those two we hid and tie them before they wake up,â Frank said, leaping from the cab.

Using the rope with which the canvas had been tied, they first secured the driverâs wrists and ankles. Just as he was coming to, they managed to gag him firmly.

âWeâd better drag him back where thereâs no possible chance of his rolling into the road and having one of the gang find him,â Frank proposed.

The driver was dragged off and wedged into a cluster of trees.

âHow about Charlie?â Joe asked. âIâll get more rope.â

âWait!â Frank said. âIâve been thinking about Charlie. He sounded as if heâs fed up with the gang. Do you suppose we could persuade himâ?â

The young man was just beginning to show signs of regaining consciousness when the boys returned to him. Frank removed Charlieâs pistol a split second before he sat up and shook his head.

âWhat happened?â he groaned.

When his head had cleared, the boys revealed their identity.

âBut I thought you wereââ

âFrozen to death in that refrigerator car?â Joe finished grimly. âNo, your boss just wasnât smart enough.â

âIâm glad of that!â Charlie growled. âI told those hombres they were goinâ too far.â

âListen, Charlie,â Frank began earnestly, âyou donât seem to be a bad sort. Why donât you quit this gang right now?â

âYou could go straight, and give us a hand in the bargain,â Joe urged.

âHow?â Charlie asked suspiciously.

âIf you help us turn the tables on those thieves, weâll do everything we can to clear you with the police.â

âBut if you stick with them,â Frank said, âthe way things are going, theyâre bound to wind up in prison for life.â

Charlie was silent, looking first at the Hardys and then off into the distance, as he thought the proposition over.

âYouâre right,â he said at last. âNowâs my chance. Maybe you wonât believe me, but I just hooked up with Flint. Lure of easy money. I ainât done anythinâ yet to get me a sentence.â He paused a few seconds. âI got two kid brothers your age. If I get caught nowâwell, I guess Iâll have to trust you about helpinâ me out. But first, what can I do?â

Elated over this unexpected source of assistance, the boys helped Charlie to his feet and discussed the situation.

âSomebodyâs got to find out about our dad,â Frank said. âFlint radioed that fellow back at the diner that Dad needed a doctor. He must be hurt! Whereâs Flint?â

âHeâs goinâ to the diner,â Charlie answered. âWeâre all supposed to meet there later.â

âHow about you going back there and finding out about my father?â Frank asked. âThen you can notify the police.â

âAnd the driver? Can you take care of him?â Joe asked.

âIâll send somebody out to bring him in,â Charlie promised. âDonât worry. You can count on me. I donât want to end up in the chair!â

It was decided that the boys would drive on to the swamp, while Charlie would walk to the main highway and hitch a ride back to the diner. As proof of the boysâ confidence in him, Frank gave the man his gun.

Charlie set off down the rough trail and the boys climbed into the cab of the truck.

âHow close do you think we ought to get to that gang?â Joe asked.

âNot too close. Weâll sneak up on foot and find out where theyâre taking this equipment.â

âThen weâll head for the cave to help Cap and Chet,â Joe added as the truck bumped and jounced along.

After that, the boys rode in silence until they saw lights ahead. Frank slowed the truck to a crawl.

âTheyâre unloading the stuff,â he said. âI would guess they are at the top of the slope above Wildcat Swamp, just opposite where we were digging.â

Several men were busy carrying lengths of pipe and heavy boxes which they were piling behind some bushes. Fortunately no one turned around when Frank braked to a complete stop.

âNowâs our chance to get away!â Joe urged. They quickly climbed out and hurried into the shadows.

By this time streaks of gray were showing in the eastern sky. With the breaking dawn to help them, the boys picked their way toward the swamp. Knowing that the thieves would be camping somewhere near it, they gave the area a wide berth as they made their way toward the sloping bank where they had been digging.

They were skirting the swamp when Joe suddenly stopped to listen. In the distance there was a low hum and rumble.

âThe trucks, Frank! They must have finished unloading. Theyâre leaving.â

âI hope Charlie gets to the diner before they do. That gangâs surely discovered by this time that he and the driver are missing. Theyâre probably searching for them right now.â

The boys pushed on around the swamp, finally completing a tortuous half circle that brought them to the bottom of the sandy slope in which the camel fossil was buried.

âSay,â said Joe as he reached the entrance to the cave, âwhat have they done to this place? Itâs choked with sand and rocks!â

âThe gang must have done it to hide the entrance from strangers,â Frank replied. âI wonder if the other entranceââ

They rushed around to the other end of the slope. The entrance there had been blocked in exactly the same way.

âThis is worse,â Joe announced. âI think the other entrance will be easier to negotiate.â

They returned to it, scrambling over the pile of sand and gravel to reach the cave opening. Before entering, Frank played the strong beam of his flashlight as far into the cave as it would carry.

âCap! Chet!â Joe called.

There was no answer.

âCome on, Frank!â

After a breath-taking slide, they landed in the mouth of the deep cavern, and flashed their lights around. There was no sign of Cap and Chet.

Dismayed and filled with apprehension, Frank began a search of the inner area. âThere may be a deeper section to this cave than we thought.â

Seconds later Joe heard his cry of joy. âTheyâre here!â

Lying in a crevice beneath the far wall, bound and gagged, were their friends. In no time, the Hardys had Cap and Chet out in the central portion of the cave.

âIâll get the gags off,â Joe said excitedly. âYou untie their hands.â

With his pocketknife he sliced the tight kerchiefs with which the captives had been gagged. Even when the gags were removed, Cap and Chet could barely whisper. They were very weak, saying they had had no food since being captured.

After all their bonds were removed, the two found that because of their long inactivity, they could not stand up. Frank and Joe massaged their numbed arms and legs to restore circulation, and in a little while the released prisoners were able to hobble painfully.

âEat some of these food tablets,â Frank said. âTheyâll help until we can get some solid food.â

A few minutes later Cap and Chet were able to give a halting, whispered account of their capture by the phony rangers.

The Hardys burned with anger when they were told that the outlaws had come back a second time to gag their captives and bind them even more securely.

âIt was then,â Cap continued with parched lips, âthat they tried to seal off the entrances to the cave. They said nobody, not even the Hardys, would see us alive again.â

âIâd like to get my hand on that Willie just once more,â Chet muttered.

âEasy does it,â Joe advised. âCome on now. We have to get out of here.â

It took a long time for Frank and Joe to get their friends out of the sand-choked passageway, but eventually all four stood on the ledge at the slope. Cap and Chet, accustomed for so long to the darkness of the cave, were almost blinded by the early-morning light.

âListen, Frank,â said Joe, âtheyâre in no condition to walk. Iâll get their horses, while you stay here with them.â

Cap laid a hand on Frankâs arm.

âNo use!â he said in a discouraged, tired voice.

âThe men took our horses. Weâre stranded!â

CHAPTER XVIII

Trapped!

FRANK shot a startled glance at Joe. The Hardys knew the seriousness of the situation and Cap sensed it too.

âYou boys go ahead to Red Butte,â he told them. âChet and I will take it easy and get there when we can.â

âBut the horses,â Chet spoke up. âYou canât go far in this country without horses.â

âOur pack mule,â Joe cried. âHe was well hidden. If the thieves didnât take him, Frank and I will ride to Red Butte and send horses back.â

âOur nearest point to contact the law,â Cap suggested, âis Sheriff Paul.â

âWe never did find out what happened at his home,â Frank reminded his brother. âSuppose we see if heâs returned. On their way back to Red Butte, Cap and Chet can stop at the Sanderson ranch to see if everything is all right there.â

Leaving Cap and Chet, the Hardys made for the campsite to look for the pack animal. It was grazing in a little natural corral. The boys threw a blanket across the muleâs back and mounted.

For a moment the mule stood still; then, at a signal from Frankâs heel, it plodded up the slope. Reaching the trail, the animal ignored a signal to turn right and doggedly trudged toward Wildcat Swamp. No amount of coaxing could change its mind.

âNow what are we going to do?â Joe asked impatiently.

âItâs just possible,â Frank reflected, âthat our mule has been used by someone else and is taking the route heâs become accustomed to. He may lead us to a new clue.â

The boys rode along without attempting to guide the animal. It headed straight for the defile, went through it, and stopped just above the spot where Cap and the boys had been digging.

âWell, what do you make of this?â Joe asked, perplexed.

Frank jumped off and started down the slope, waving to Joe to follow.

âSomebody else has been digging hereâthey even put up a sign!â he cried.

â âDanger,â â he read aloud. â âExplosives buried. Keep out.â â

âI wonder if thatâs a trick to scare people away from here,â Joe pondered.

âWeâd better not stop to find out,â Frank replied. âBut I think we should warn Chet and Cap in case itâs true.â

This time the mule willingly carried the boys in the opposite direction. Reaching camp, he turned in.

âSomebody sure has been using this mule recently,â Frank said. âI wonder if it was to carry dynamite.â

âSure looks like itâif the sign means anything,â Joe answered.

At that moment Cap and Chet wearily arrived at the camp.

âWhatâs up now? I see you found the mule, but why did you come back?â Chet asked.

Quickly the Hardys explained and urged their friends to stay away from the pit.

When Cap agreed, Frank and Joe started off again. Reaching the trail, their mule once more turned left.

âOh, no, not again,â Joe cried, trying his best to guide the animal to the right.

âNow what?â Frank pondered. âItâs a long walk to Sheriff Paulâs.â

Joe broke a leafy twig from a sapling and remounted. âFrank, you walk ahead the way we want to go. Iâll see what I can do from here.â

His brother took the lead rope and started. The mule walked four steps, then stopped. Joe tickled its ear with the twig. As the muleâs attention was distracted, Frank coaxed it a few feet farther.

The boys continued this maneuver until the animal seemed to lose interest in going back. There was no more trouble and Frank climbed up behind his brother.

Meanwhile, Cap and Chet were at a loss. Without horses they certainly would not be able to go far.

Sitting before their tent, Capâs far-roving eye spotted a movement on the hillside.

âWhat are you looking at?â Chet asked.

âIâm not sure, but Iâm beginning to work up a hunch,â Cap said. âCome with me.â

As they scrambled down the incline, Cap let out a cry. âI was right! Our horses!â

The two mounts were tethered in a grove of pine trees.

âSo this is where those phony rangers hid them!â Chet exclaimed.

âNow we can do a little traveling of our own!â Cap cheered. âLetâs get started for the Sanderson ranch.â

Stiffly they swung into the saddles, and a minute later were loping along the trail.

While all this was happening, Frank and Joe were still swaying from side to side on the back of the mule. Without a horse to follow, the mule ambled along at a pace of his own choosing.

After three hours of stumbling over sand-covered rocks and sliding along bare shale, the mule brought the boys in sight of the sheriffâs ranch.

âI hope somebodyâs here,â Joe said, âto give me a tall glass of water.â

Dismounting, the boys tied the mule behind the barn and went to the door of the ranch house.

âHello!â they called. No answer.

âLooks exactly as it was before,â Frank said, pushing the door open.

Seeing their note lying on the table, the boys went through to the kitchen. The unwashed dishes still rested in the sink and the basket of clothes remained untouched.

âItâs obvious that Mrs. Paul hasnât been back here,â Joe said. âShall we start for Red Butte?â

âYes, but through open country. I donât want to be trapped again.â

As the two boys crossed the living room, Joe noticed something strange. âSay, the radiotelephoneâs gone,â he said.

âThat means somebody has been here since we left,â Frank stated.

Before the Hardys could ponder the riddle further, a distant clatter of hoofs caused them to glance out the window. Three riders in green uniforms were galloping up to the house.

âThe fake rangers!â Frank warned. âWeâd better get out of here.â

The boys hurried through the kitchen, closing the back door quietly behind them, then crossed the yard rapidly and hid inside the stone-and-rail corral attached to the barn.

No sooner had they concealed themselves than the men galloped up and dismounted. Through a crack in the corral fence, the boys could see that one of the men was short, wiry, beady-eyed Willie the Penman! The flat-nosed, fierce-looking man with the craggy brows obviously was Snide.

Willie gave a laugh of satisfaction. âThis is a snap with the sheriff out of the way, Snide,â he said. âHe sure bit on that âmissing rangersâ gag.â

âWillie,â Snide said, âI have to hand it to you. The sheriff walked right into that one. Nobodyâd ever look for him in the tower.â

Nudging his brother, Joe whispered, âI wonder where this tower is theyâre talking about.â

Willieâs whining voice continued. âWe canât stick around here long. Iâll get those seals Iâll need to make the papers look legal. Somebody mightâin fact, somebody is coming. Itâs that Sanderson kid. Quick! Take off those uniforms. Pretend youâre waiting for the sheriff. Iâll hide in the barn.â

Frank and Joe watched Willieâs companions strip off the rangersâ uniforms, revealing cowboy outfits underneath. Willie carried the discarded clothes through the open barn door.

Harry rode up to the men, who greeted him in a friendly manner.

âIâm looking for the sheriff,â the boy said. âI need his help.â

âWeâre waiting for Paul ourselves,â Snide answered. âWhatâs your trouble?â

Frank and Joe clenched their fists, hoping the boy would say no more. But Harry continued earnestly:

âWell, a couple of days ago two boys promised me theyâd help Mom find a way to keep her land. They had a campsite near Devilâs Swamp and have disappeared. I want Sheriff Paul to help me find them.â

âNo use,â Snide said. âThose boys named Frank and Joe told me they were going back to their home in a place called Bayport. You might as well go home yourself. Just wasting your time here.â

Harry looked surprised when he heard the Hardys mentioned, but still seemed undecided. âIâve got to see the sheriff,â he insisted.

âIâll give him your message, kid.â

âWell, okay.â The boy wheeled his horse and rode slowly past the corral on his way out.

âNowâs my chance,â Joe whispered to Frank.

Crouching low and running as quietly as possible he came to the far corner just as Harry did and peered through the bars.

âPretend you donât see me, Harry,â he said in a loud whisper. The boy stiffened. âThis is Joe Hardy. Get off your horse and act as if youâre tightening the cinch.â

Without looking toward Joeâs hiding place, the boy dismounted and began adjusting his saddle.

âYouâve got to get to Red Butte for help,â Joe continued. âThese men are in with the gang thatâs after your land! Theyâre holding Sheriff Paul in a tower. Hurry!â

Harry played his part well. He nodded slightly, mounted his horse, and trotted away. Leaving the ranch, he spurred the animal into a gallop. Harry rode at breakneck speed for a mile, then slowed down to rest his horse.

About to resume his fast pace, Harry saw two riders approaching. They guided their horses on either side of him and one man grabbed his reins.

âWhoa, there, kid!â the larger of the two husky riders said. âWhere are you going in such a rush?â

âTo town,â Harry blurted out. âThereâs a gang of crooks trying to steal Momâs land and theyâre holding Sheriff Paul a prisoner!â

âHowâd you find all this out?â the other man asked.

âJoe Hardy told me. He and his brother Frank are hiding at the ranch right now. Youâve got to help us!â

âOh, weâll give you a hand, all right.â He turned to his big companion. âGive him both hands!â

The man seized Harryâs wrists and tied them behind his back. He lashed the boy around the waist to the pommel of his saddle and hobbled his horse with a length of rope. The animal would be able to move only a few inches with each stop.

Harryâs eyes were wide with fright. âWhatâs the idea? You must beââ

âThatâs right, kid,â the big man said. âYou talk too much to the wrong people.â

Leaving Harry helpless, the men then whipped their horses and galloped on toward the Paul ranch.

Back in the corral, Frank and Joe were still crouching behind the fence. Willie the Penman had gone into the ranch house, but the others remained outside.

There was the clatter of hoofbeats.

âTwo men!â Joe whispered, peering between the bars at a pair of riders cantering toward the house. âThey canât be reinforcements sent by Harry. Itâs too soon for that.â

When Willie and his henchmen recognized the newcomers, they stepped out to meet them. The men spoke in low tones that did not carry to the corral fence.

âThis doesnât look good!â Joe warned. âLook! Theyâre fanning out all over the place as if to cut off our escape.â

âSnide is coming this way!â Frank exclaimed, crouching lower.

Stalking cautiously around the corner of the fence where Joe had talked to Harry, Snide turned along its near side. As he reached the end, the boys quietly retreated toward the barn. A few yards more and they could make a run for it.

Suddenly there was a shout from behind them.

âThere they are!â

Whirling, the boys found two big cowboys between them and the barn.

Snide ran toward them from the other side.

Frank and Joe were trapped!

CHAPTER XIX

To the Rescue

SNIDE, seeing the Hardys, twisted his mouth to one side and called:

âCome on, Willie!â

The wiry little figure of Willie the Penman rounded the corner, followed by a hulking cowboy.

Frank and Joe delivered a couple of stiff punches, but the odds were against them. The battle was over almost before it began.

Wiping the sweat from his face, Willie stood before Frank and Joe, held firmly in viselike grips by his companions.

âSo you got out of the cooler, eh?â he whined. âWell, wise guys, you wonât outsmart us again!â

Turning to the other men, he ordered, âTie âem upâtight!â

Two men went to the barn and returned with lengths of bailing wire. Twisting it roughly around the boysâ wrists and ankles, they made certain that Frank and Joe could not move.

Willie said to Snide, âIâm ready to take off. Just be sure these kids donât pull any fast ones.â

âDonât worry,â Snide replied. âTheyâre going to stay put.â

âOkay. Iâm late now. Mrs. Sanderson will be heartbroken if I donât keep our little date.â

âSure you got all the papers for her to sign, Willie?â Snide asked. âNow that weâre getting this close, we donât want no slip-up with the law.â

âIâm no amateur,â Willie said, annoyance in his voice. âSheâll sign everything legal and proper. If she donât, Iâll tell her about Harry!â

The boys looked at each other in mystified silence. What had Willie meant? Was Harry Sanderson in trouble? If so, that would mean he had not delivered their message for help.

Willie called for one of the horses and rode off in the direction of the Sanderson ranch.

The rest watched until he was out of sight, whereupon Snide turned to the Hardys.

He prodded Joe with a foot. âHowâd you jerks get here, anyway?â he rasped.

Receiving no answer, he continued, âOh, more heroic guys, eh, like your friends in the cave?â

He was interrupted by a sudden shout. âHey, hereâs how the bozos got here!â

One of the cowboys appeared from behind the barn, leading the mule. âAinât this the critter we snatched?â Snide asked. âWeâll use him to carry more dynamite,â he added. âLetâs move.â

âWhere to?â

âWeâll hit the swamp and check up on the oil-rig stuff before we start drilling.â

Frank was thrown over the front of Snideâs horse, and Joe against the pommel of a cowboyâs mount. Doubled up in this uncomfortable manner, they were carried toward Wildcat Swamp.

By the time they came in view of the ridge overlooking the swamp, the boys were aching in every muscle.

âKeep these kids tied up,â Snide ordered, âand haul âem down with us.â

The party descended from the narrow ledge toward the pit in which the fossils lay. There, still firmly in place, was the ominous sign: DANGER. EXPLOSIVES BURIED.

âOne move out of you guys, and youâre dead pigeons,â Snide warned. âThis place is loaded.â

Frank and Joe were dragged from the horses. They were made to sit down on the ground, with their backs against rock shafts. Then they were securely tied to the shafts.

In plain sight, across the swamp, sloped the heavily wooded mountain. Barely jutting above it, like a tiny cheesebox, was the old fire tower.

Frank and Joe shared the same flash of understanding. This must be the tower Willie had mentioned back at the sheriffâs ranch.

Twisting slightly, Joe tried to catch Frankâs eye. But the movement arrested Snideâs attention.

âListen!â he growled. âI warned you two about moving around. Cut it out! We want you alive when your father gets here. Then weâll take all three of you to the tower andââ

Boom!

The blast thundered between the hills that surrounded Wildcat Swamp, echoing over the valley. Snideâs flat nose purpled in growing anger.

âWhat idiot set off that dynamite ahead of time?â he roared. âIâll break his fool neck.â

âNot that foolâs neck,â one of the cowboys said sardonically. âHe probably blew himself to bits.â

âYeah? Well, weâre lucky that mountainâs still there! What you cowpokes donât know about explosives would fill a book!â

âDonât get upset, Snide,â the cowboy said reassuringly. âThereâs plenty more dynamite left.â

âIâll check on that myself,â Snide said importantly. âAnd maybe we wonât put off the business of the tower any more, either. We can take care of the Hardys another way.â

The outlaws mounted their horses, and, riding down the slope toward the edge of the swamp, soon were out of sight.

Frank and Joe looked at each other. âIf they stay away long enough, Cap and Chet may come here and rescue us,â Joe said.

âI sure hope so!â Frank said.

âDo you believe that stuff about explosives being buried here?â Joe queried.

âThey sure didnât seem to walk around very carefully,â Frank observed. âAnd even if there is dynamite buried here, I donât believe it can be set off just by stepping on it. They were hoping to scare us into sitting still.â

âI guess youâre rightâand that means we can try to get loose!â

Encouraged by this idea, they struggled hard with their bonds.

âTry rubbing the wire up and down on the rock,â Joe suggested. âMaybe itâll snap.â

But this was a hopeless effort. Every movement they made only rubbed skin off their wrists. Time dragged on and nobody came.

Frank had lapsed into thoughtful silence. He began going over the entire mystery, step by step. When his mind conjured up the picture of the three phony rangers, dressed in their ill-fitting uniforms, he suddenly exclaimed:

âJoe, we have to get over to that tower, pronto!â

âWhy?â

âI have a hunch,â Frank said excitedly. âFrom what Snide said, I figure three real rangers are imprisoned thereâand Sheriff Paul, too!â

âI get it,â Joe said. âThe men whose uniforms they stole.â

âRight,â Frank continued, âand after Willie got all the papers signed, the rangers were going to be released. But not now. I think weâve forced their hand.â

âHow?â

âWe came along and found out whatâs going on,â Frank reasoned. âNow those thieves will have to do away with every one of us.â

Cap and Chet, meanwhile, still sore and stiff after their captivity in the cave, were riding toward the Sanderson ranch house. Approaching it, Chet pointed to a horse tethered in front.

âThatâs not Harryâs,â he said, reining in.

âThen weâd better find out whoâs here before we barge in,â Cap decided.

âIf we tie our horses among these trees,â Chet suggested, âwe can slip up to the house from the other side of the barn and look in.â

It took several minutes for them to circle around and approach the place from its blind side. Peering from the shadow of the adjacent barn, neither Cap nor Chet could see anyone. Stealthily they tiptoed across the yard and crept to an open window.

Cap cautiously raised his head until his eyes were on a level with the sill. He peered into the Sanderson living room. Almost immediately he ducked, turned, and waved to Chet to take a look.

Chetâs hurried glance revealed Willie the Penman, seated at a table with Mrs. Sanderson. The forger was handing her a pen.

âYou may as well sign this document,â Willie was saying, âand get it over with.â

âOh, I wish my husband were still alive!â Mrs. Sanderson sobbed. âHeâd know what to do.â

âHarry says itâs best,â came Willieâs high-pitched tones. âAnd he talked it over with those Hardy kids.â

Capâs hand tightened on Chetâs shoulder. The science teacher pointed to the ranch-house door, standing ajar. Silently they crept to the entrance.

âOh, all right, give me the pen. Iâll sign,â they heard the bewildered woman say resignedly.

âNow!â Cap commanded, and charged into the house with Chet behind him.

Like twin thunderbolts, they landed on Willieâs back. Surprised, the wily criminal tried desperately to pull his gun. But Chet knocked it across the room. Ten seconds later Willie was stretched out helpless on the floor.

âDonât be frightened!â Cap told Harryâs terrified mother. âWeâre friends of the Hardy boys,â and he introduced himself and Chet. âThis forger,â he went on, âhas been trying to bilk you out of your land.â

After Cap had explained the situation to Mrs. Sanderson, the woman burst into tears of relief.

âHave you seen Harry?â she asked.

Before Cap or Chet could answer, Willie suddenly spoke up. âI know where he is! In trouble! And so are Frank and Joe Hardy.â

âWhere are they?â Cap demanded.

âWill you let me go if I tell you? Give me a half hourâs start, and I promise I wonât go back to the gang. And Iâll tell you how to save the three kids.â

Cap and Chet looked at each other, then at Mrs. Sanderson.

âCan we believe him?â she asked.

âI wouldnât trust this man any farther than I can throw him!â Chet said. âHeâd go right to the gang and warn them, and thereâs no telling what theyâd do to our friends.â

âHeâs right,â Cap said to Mrs. Sanderson.

Just then there was the sound of hoofbeats outside. Hurrying to the window, the woman exclaimed, âItâs Mrs. Paul and two deputies!â

The sheriffâs wife said she was searching for her husband. âIâm afraid heâs lying hurt somewhere, so I asked Bill and Ted to help me find him.â

âWhy donât you stay with me?â Mrs. Sanderson suggested. âBill and Ted can take this thief to Red Butte and lock him up.â

Cap, who did not put much stock in Willieâs dire assertion, nevertheless asked the deputies to find out if the Hardys had reached Red Butte. He and Chet would go back to the fossil pit in case Frank and Joe should return.

âAnd please look for Harry,â Mrs. Sanderson begged the deputies.

The lawmen nodded and left with their glowering prisoner. Chet asked Mrs. Sanderson if they might borrow some tools, and after getting them, he and Cap started for the fossil area.

Meanwhile, Frank and Joe, sitting against the rocks to which they were bound, heard furtive footsteps in the defile above them.

âSomebodyâs coming!â Joe warned.

Listening intently, they heard the clatter of a dislodged stone. Then, as a head came cautiously into view around the ledge, Frank and Joe shouted in relief.

âHarry Sanderson! Hurry up and untie us!â

While untwisting the Hardysâ wire bonds, Harry was told what had happened to them. Then he in turn related the story of his own capture.

âHowâd you get loose?â Frank asked.

âRolled off my horse and cut the ropes on a sharp rock. I figured it would be too late to get help for you boys. So I rode back to the Paul ranch. When I saw all the hoofprints headed this way, I was sure you were prisoners, so I came along.â

After the Hardys had told Harry the news about Willie, Joe pointed to the old fire tower.

âOur problem,â he said, âis to get to that place without horses. We think the sheriff and three rangers are being held up there.â

âItâs not as great a problem as you think,â Harry said. âI know a safe way through the swamp. Follow me.â He hid his horse in a thicket and set out on foot.

Harryâs route to the tower was surprisingly short. He seemed to have an uncanny knowledge of the bog, leading the Hardys along high spots and across a series of hummocks. Soon the three stood at the foot of the mountain and looked up.

It seemed like an impossible climb, but the boys started up the steep slope on hands and knees, Sharp rocks cut their boots, and saplings which they grabbed for support pulled out of the thin soil. Finally they clambered to the flat stretch of ground on which the fire tower was built.

The gray, rickety wooden structure, standing in the center of a clearing bounded by scrubby trees, seemed to be deserted.

The boys looked around for possible guards, but none were in sight. Cautiously the three advanced and went to the door in the base of the tower. It had been forced open and hung by one hinge.

Frank and Joe stepped gingerly inside. Harry followed.

âStand guard,â Frank told the boy.âYell if anyone shows up, then run to a safe place.â

Harry took up a position behind the broken door as Frank and Joe started to climb the creaking wooden stairway.

âI hope these steps hold us, Joe!â

The stairs clung to the wall, ascending in steep, right-angled turns. At each step the Hardys took, the tower trembled.

Finally they reached the floor of the observation tower. No one was there.

âGuess we were wrong,â said Joe.

âMaybe not.â

Gazing at the ceiling, Frank noticed that the boards did not match exactly.

âJoe! I believe thereâs a trap door up there! Give me a boost.â

As Frank climbed to Joeâs shoulders, there was a sudden pounding above him. Then muffled cries of âHelp! Help!â

Frank put his shoulder against the trap door and heaved. It yielded and he pulled himself up through the opening.

A strange sight greeted him. On the floor lay four unshaven, disheveled men, securely bound, but without gags. Three of them wore ill-fitting shirts and trousers. The fourth, a blond, ruddy man, was dressed in blue jeans, a plaid shirt, and a vest with a sheriffâs silver star on it.

As Frank pulled Joe up through the opening, the man with the star greeted them weakly. âIâm Sheriff Paul. These men are rangers.â

âWeâre Frank and Joe Hardy. You have to get out of hereâfast!â Joe said quickly. âThe tower may be blown up any minute!â

With lightning speed, they unbound the prisoners and helped them down to the observation tower. The released men, hardly able to stand, crawled down the stairway.

As they made the perilous descent, Frank and Joe asked, âWho brought you here, Sheriff?â

âAll I know is that I received a phone call about some missing rangers. When I went to investigate, three men jumped me.â

âOur dadâs been captured, too,â Frank said as they neared the base of the tower. âHe was after a gang of train robbers when they got him.â

âIs Fenton Hardy your dad?â

When the boys nodded, the sheriff said warmly, âMr. Hardy has a great reputation among us lawmen. I sure hope no harm has come to him.â

The minutes required to reach the bottom of the tower seemed like hours, but finally Joe hit the last step. Harryâs eyes popped when he saw the sheriff and the rangers. When the boy reported that nobody had come in view, Frank urged, âQuick! Run for it. This place may be dynamited any minute!â

No sooner had they dashed through the doorway to the edge of the clearing than they heard an ominous rumble.

âDown!â Frank shouted. âCover up!â

As they pitched themselves headlong, the earth behind them split open with a shattering roar. The tower bulged at the bottom and started to collapse.

CHAPTER XX

The Roundup

âSAFE!â

Sheriff Paulâs whisper broke the silence after the tremendous blast and crash of the tower.

As they all looked back in awe at the mass of debris, one of the rangers said, âIf weâd even been in the clearing, we might have been killed.â

âThe danger isnât over yet,â Sheriff Paul reminded them. âThat gang will be coming up to check on their job. Letâs put some distance between them and us!â

Hurriedly the group moved cautiously down the steep slope, finally stopping to rest in a quiet glade near the base of the mountain.

âWith Chet and Cap out of the cave, the next step is to find Dad,â Frank proposed.

Then the brothers told about their escape from the refrigerator car, the train wreck, and the capture of one of the truck drivers. When they related how they had persuaded Charlie, the driverâs helper, to help them, the sheriff showed keen interest.

âYou say his name is Charlie? Say, that might be Charlie Brace, one of the local boys here.â

When the Hardys described their new ally, the sheriff nodded. âThatâs Charlie, all right. A nice young fellow, but heâs been getting mixed up with a bad crowd lately.â

âWell, now heâs going straight,â Joe said. âAt least we hope he is.â

After discussing what their next move should be, it was decided that they would go to the site where the oil-drilling equipment was cached.

âNo doubt weâll find some of the gang there,â the sheriff observed, âand maybe we can surprise them and nab a few at a time.â

They had barely started in the direction of the gangâs stockpile when they heard the distant rumble of a motor.

âSounds like a heavy truck,â Joe said.

âMust be on that old logging trail over the next rise,â the sheriff said. âHurry. Weâll see who it is.â

Careful to conceal themselves in the natural cover, they reached the old trail in time to see a truck stop a short distance away. The driver hopped out.

âCharlie!â the Hardys gasped, and Sheriff Paul nodded. Had he kept his promise? the boys wondered as they watched his actions.

The young fellow seemed to be waving at someone he could see through the trees. Four men emerged from the woods to join Charlie in the road.

Turk, Snide, and two others!

For a couple of minutes the five men stood talking in the center of the road.

Suddenly the back gate of the truck fell with a clatterâand out poured a swarm of men!

Frankâs eye caught the foremost of the new arrivals. âDad!â he shouted.

âJack Wayne and Sam Radley!â Joe yelled in astonishment.

At the same time the detectiveâs posse surrounded Turk, Snide, and the other two outlaws, disarming them and snapping handcuffs on each of them.

Charlie had kept his promise!

Overjoyed, the onlookers emerged from their hiding place. For a moment, all was confusion as Fenton Hardy greeted his sons and their friends.

âBut, Dad, we thought you were hurt!â Frank exclaimed.

âNo. Jack and I had a rough time, but we won the fight at the plane. Then I made Flint broadcast the story about our capture, to throw the rest of the gang off. Flintâs in jail, and so is Snake Fliegel.â

âWhoâs Fliegel?â Frank asked.

Stepping forward with a smile, Charlie Brace said, âDonât you know him? Fliegel is the one who followed you from Bayport to Green Sand in his plane.â

âThe black-eyed character who slithers along like a snake!â Joe exclaimed.

âThatâs the guy,â Charlie continued. âHe was in with Flint and Willie long before any of us local chaps got mixed up in the affair. Flint told me the whole story.â

âHowâd he get started after the oil?â Frank wanted to know.

âFlint used to travel around the country a lot,â Charlie explained, âridinâ the rails and scratchinâ out a living where he could. He was doinâ pretty well in a small town somewhere in the West when he ran into a sick, old wildcatter.â

Turk glared at the man who was turning stateâs evidence, but Charlie continued:

âThis old fellow claimed his memory had just returned after a long siege of illness. He was broke, but he said that if Flint would stake him until he could get a job he would tell Flint a tale that might make him rich.â

âAnd Flint believed him?â Joe asked.

âHe figured it was worth a gamble,â Charlie said. âAnyway, the old man told Flint that fifty years before he had been one of a group of wildcatters who had found a rich deposit of oil. But they had had bad luck. A cave-in buried twenty of âem. Only the old man escaped.â

âSo thatâs what the sign meant,â Frank said.

âYes. The poor wildcatter nailed the sign over his friendsâ grave. The shock was too much for him, though, and he lost his memory.â

All the listeners crowded close around Charlie to hear the fantastic story.

âAfter Flint had staked him to a place to live and had stocked it with food, the old man led him to the spotâthe place youâve been callinâ Wildcat Swamp. Shortly after that, the poor chap died.

âBefore he could do anythinâ about the oil, Flint was caught in a train robbery and was sent to prison. Thatâs where he met Willie.â

âI wonder why he decided to share the loot with that creep,â Joe remarked.

âWell,â Charlie said, âI guess he figured Willie would be able to forge the documents to get the land away from Mrs. Sanderson. Then they added Turk because he knew something about engineering.â

âHow did Snide fit in?â Joe asked with a glance at the glowering captive.

âHe was an old friend of Willie and an experienced oil man. They contacted him and he brought Snake Fliegel with him. They gave Snake the job of trying to stop you and Cap Bailey from finding the swamp. He was the one who tampered with your plane so it would crack up before you got off the ground.â

âJack outfoxed them on that one.â Joe grinned and saluted Wayne.

âYes,â Charlie said, smiling. âWhen he flew off and left you at Green Sand Lake, Flint and Turk didnât know what to make of it. They followed you in Fliegelâs plane, and Snake was on hand to help them break out of the jail there. Then he piloted them to a field outside Red Butte.â

âThatâs where we came in,â one of the rangers spoke up. âWe saw his plane land and noticed it had no license number. We investigated and found these cowboy friends of Snide meeting the plane. Our interest must have scared them.â

âRight,â said another ranger. âThey held us at gunpoint, stole our uniforms, and shut us up in that old tower.â

âDonât blame it all on us,â Turk snapped. âThe cowpokes had plenty to do with this deal. They toppled that big boulder over, and sent the fake message to the sheriffâs office. Then they called on his wife and fouled up his radiotelephone, returning later to steal it.â

Frank and Joe listened intently to this recital, which pieced together various parts of the mystery. A few more questions cleared up the rest of the nefarious plot.

They learned that it was Willie and Snide who had read the story about Baileyâs fossil hunt and had held up Cap in his car; it was Snide who had shot down the antenna balloon. The skeleton, Charlie said, had been planted in the cave to scare off intruders.

After congratulating his sons on solving the mystery, Mr. Hardy said, âWe ought to go to the fossil pit now and find out how Cap and Chet are.â

Several members of the posse were commissioned to take Turk, Snide, and his henchmen off to join Flint and Fliegel in jail.

Then the rest of the group started for the swamp. They had gone about halfway when they met Mrs. Sanderson and Mrs. Paul riding toward them.

âWe have good news for you,â said Mrs. Sanderson. âYour friends Cap and Chet captured Willie the Penman just as he was trying to force me to sign away my property.â

When they heard this news Frank and Joe let out a whoop.

âYou have nothing more to fear now,â Mr. Hardy told Mrs. Sanderson. âIâll be glad to get a reputable oil company to check on the old wildcattersâ theory of a large oil deposit here.â

Soon the party reached the foot of the sandy slope in which the camel fossil was buried. There was the sound of pick and shovel from the pit, and in answer to Frankâs âHallooâ two heads popped up over the rim.

âI certainly am glad to see you all with a whole skin!â Cap declared as he shook hands with the Hardys.

Frank and Joe grinned. They had indeed pulled themselves out of a tight fix. Not many weeks were to elapse before they again found their lives in danger while trying to solve the mystery of The Crisscross Shadow.

âWait till we tell you whatâs happened here,â Chet said with pride.

âNow what?â Joe inquired.

âRemember when that first explosion went off? Well, we could feel the earth shaking and heaving way over here. We happened to look down into the old cave, and you should see it now.â

âIt was like a little earthquake,â Cap added. âThe explosion opened a subterranean cavern as beautiful as any. Itâs full of gorgeous stalactites and stalagmites. Mrs. Sanderson, you own a very valuable piece of property even if it turns out that there isnât a drop of oil on it.â

âSure,â Chet said, âand we were the first sight-seers. Now I qualify for a job as guide.â

âA guide!â Joe needled. âYou have a job back homeâhow about that swimming pool?â

âYou fellows ran out on me,â Chet said reproachfully. âAfter all the help Iâve been to you, I should think youâd want to dig it for me.â

âIâll help you,â offered Cap, âas soon as we dig up my camel fossil.â

Chetâs eyes shone.

âFrank, Joe, you heard the man!â he exclaimed. âLetâs go!â