THE SECRET OF PIRATESâ€™ HILL

In a series of hair-raising adventures both on land and undersea the teen-age brother detectives pit their wits against some of the most ruthless criminals they have ever encountered.

It all starts when Frank and Joe are skin diving just for fun and the thrill of exploring the undersea world. Suddenly, deep in the waters that flow near the foot of Piratesâ€™ Hill, a mysterious skin diver fires a spear through Frankâ€™s air hose.

From this moment on, danger is never far away. The very lives of the boys are at stake as they, with the help of their pals Chet Morton and Tony Prito, uncover a mystery involving an old Spanish cannon and a fabulous sunken treasure. Again, Franklin W. Dixon has woven a suspense-filled story that will thrill his many fans.

A rocket was streaking directly toward them!

Copyright Â© 1972,1956, 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 HARDYB0YSÂ® is a registered trademark of Simon & Schuster, Inc.
GROSSET & DUNLAP is a trademark of Grosset & Dunlap, Inc.
Library of Congress Catalog Card Number:72-77108

eISBN : 978-1-101-07650-7

http://us.penguingroup.com

CHAPTER I

Underwater Danger

âDONâT forget, Frank, any treasure we find will be divided fifty-fifty!â Blond, seventeen-year-old Joe Hardy grinned. He checked his skin-diving gear and slid, flippers first, over the gunwale of their motorboat.

âIâll settle for a pot of gold,â retorted Frank.

He was similarly attired in trunks, air tank, and face mask, and carried a shark knife. The boys had anchored their boat, the Sleuth, off a secluded area of dunes, which ran beneath a low, rocky promontory called Piratesâ Hill.

âHere goes!â said Frank as he plunged into the cool waters of the Atlantic. Together, the Hardys swam toward the bottom.

Suddenly Joe clutched his brotherâs arm and pointed. Twenty feet in front of them and only a short distance from the surface was another skin diver in a black rubber suit. The barbed shaft of a spear gun he held was aimed in their direction!

As the man pulled the trigger, Joe gave Frank a hard shove, separating the boys. The arrow flashed between them and drifted away.

âWow! Whatâs that guy trying to do?â Frank thought as the diver moved off. âHe couldnât possibly have mistaken us for fish!â

Motioning for his brother to follow, he swam toward the diver. But the spearman, with powerful strokes, shot to the surface. Apparently he did not want to be questioned.

Pointing, Frank indicated to Joe, âUp and after him!â

As they popped above the waves, they looked about. The Sleuth lay twenty feet away. But the spearman was nowhere in sight.

Frank and Joe lifted their face masks. âWhere did he go?â Frank called out.

âBeats me,â Joe replied, treading water and gazing in all directions.

Conjecturing that the stranger must have swum slightly beneath the surface and taken off toward shore, the Hardys decided to give up the chase and resume their diving.

âDown we go,â Joe said as he readjusted the straps that held the air tank on his back. âBut keep your eyes open for that spearman.â

âRight.â

Again the boys submerged. There was no sign of the other diver. âHe sure got away from here fast,â Frank thought. âI wonder who he is.â

Long, strong strokes with their rubber-finned legs forced the boys downward through seaweed gardens. Small fish swished in and out among the fronds. Seeing no interesting objects to salvage, Frank signaled Joe to head for deeper water. Air bubbles rippled steadily upward.

Moments later Frank felt a sudden jar and his face mask was nearly ripped off. He clawed desperately to put it back in place, but realized that his air hose had been ripped. Frantically he tried to move up, but unconsciousness swept over him.

Joe, who had seen the whole episode, was horror-struck. Another shaft from a spear gun had zipped through the murky deep. From the vast amount of bubbles rising through the water, Joe knew that his brotherâs life was in danger.

With powerful strokes, he reached Frankâs side. Towing the limp form with one hand, Joe headed for the Sleuthâs anchor line, dimly visible in the distance. Working his fins as violently as possible, he fought his way toward it for what seemed an eternity.

Finally he reached the rope and pulled himself to the surface. Joe tore off Frankâs headgear, holding his face above the waves. Then he pushed him into the boat and scrambled aboard.

Quickly Joe laid his brother in a prone posi. tion and applied artificial respiration.

Minutes passed before Frank stirred. Joe continued his treatment until he heard a moan, then a feeble question.

âWhereâ? What happened?â

âWe were shot at again and you were hit,â Joe said, helping Frank sit up.

âThe same diver?â

âMust have been. Probably he was hiding behind an underwater rock,â Joe replied.

âThat guy must be crazy!â Frank said, after filling his lungs with deep drafts of air.

âI canât figure him out,â Joe mused. âDo you suppose heâs looking for sunken treasure and wanted to keep us away?â

âI never heard anybody talk about sunken treasure off Bayport,â Frank said.

âNo,â Joe agreed. âWell, pal, I think youâve had enough for one morning. Letâs go home.â

He pulled up anchor and started the motor. Two miles away on Barmet Bay was the boathouse where the boys kept the Sleuth. As. they turned toward the bay entrance, Joe grinned ruefully. âI wish we could have kept that spear for a clue,â he remarked, âbut it passed clean through your air hose and disappeared.â

âI did notice one thing when we chased the diver,â said Frank. âThere was a yellow band around that black swim cap he wore.â

Frank realized his air hose had been ripped!

âPretty slim clue. You feeling okay, Frank?â

Frank said he felt a bit nauseous, but otherwise recovered from the shock. âHey,â he added, âthereâs someone waiting for us at the dock!â

Drawing closer, they saw a man about thirty-five years old. He was tall, broad-shouldered, and had wiry black hair. He stood motionless, his legs braced apart, looking intently at them.

Joe ran the Sleuth into the boathouse and the brothers stepped ashore.

âGood morning,â the stranger said as they came outside. âMy nameâs Clyde Bowden. Iâm from Tampa, Florida. I assume youâre the Hardys?â

âThatâs right,â Frank replied as the trio shook hands. âWhat can we do for you?â

âA detecting job.â

âLetâs hear about it,â Frank said.

The Hardys, star athletes at Bayport High, were the sons of Fenton Hardy. Formerly a crack detective with the New York City Police Depart ment, Mr. Hardy was now an internationally famous private investigator. Frank and Joe often helped their father on his cases and also had solved many mysteries on their own.

Their first big success was The Tower Treasure, and only recently they had had several hair-raising adventures in tracking down The Clue in the Embers. Now they were excited about the prospect of tackling a new mystery.

âHow did you know where to find us?â Joe asked.

âI just left your home on Elm Street,â Bowden replied. âLearned from your mother I might meet you here.â

âWhile we stow our diving gear and get into some clothes, suppose you tell us about your case,â said Frank.

The boys put their skin-diving equipment in a locker of the Sleuth, then pulled on shirts, dungarees, and sneakers.

They listened intently as Bowden explained that he was searching for an early eighteenth-century cannon known as a Spanish demiculverin. It was supposed to be in the vicinity of Bayport.

âA Spanish cannon in Bayport?â Joe asked unbelievingly.

âAlthough Iâm not in a position to tell you how I know about the cannon, Iâm certain that with your assistance I can locate it,â Bowden answered.

As they drove toward the Hardy home, Frank asked the man for the dimensions of the cannon. Bowden described it as being nine feet long and weighing 3,200 pounds. âIt fires an eight-pound shot,â he added.

âWhat do you want the old cannon for?â Joe asked.

Bowden smiled. âBelieve it or not, Iâm helping to outfit the pirate boats to be used in the famous Gasparilla Exposition in Tampa this year,â he replied. âAll the details, including the guns, must be authentic.â

âThatâs very interesting,â said Frank as they turned a corner toward the town square. âI should think that the type of cannon youâre look ing for would be found somewhere around the Caribbean rather than this far north. Iâve read that many Spanish ships were wreckedââ

Frank stopped speaking as a deafening boom suddenly shook the air.

âWhat was that?â Bowden gasped.

âIt came from the square,â Frank replied. âSounds like trouble. Come on!â

Frank drove quickly around another corner and parked the car. They all jumped out.

CHAPTER II

A Suspicious Client

WITH Bowden trailing behind, Frank and Joe sprinted toward a crowd of people milling in the town square. They were gathered around an old Civil War mortar that stood on a pedestal. White smoke drifted from the muzzle.

âSomebody fired the gun!â Joe cried out.

âIt must have been an accident,â Frank said.

As the boys shouldered their way through the crowd they saw Officers Smuff and Riley of the local police force being besieged with questions from the onlookers.

Before the policemen could reply, a booming voice sounded above the babble and a short, grizzled old man, dressed in a revolutionary Minute Manâs costume, complete with tricorn hat and leggings, strode up beside the mortar.

âI canât understand what all this here fussin is about,â he said in a booming voice.

He smiled and his weather-beaten face creased into long lines. He told Officer Riley that he was Jim Tilton, a retired artillery sergeant. He had been asked by Police Chief Collig to take charge of the Independence Day cannon salute.

âBut this isnât July fourth!â Riley protested. âItâs only the first.â

The old-timer raised his hands good-naturedly. âIâm mighty sorry I caused so much fuss. After all, I wasnât usinâ a ball. I just had some powder anâ waddinâ in her.â

Tilton pulled a letter from his pocket and showed it to the officers. It was from Police Chief Collig and the Fourth-of-July Committee, granting permission for Tilton to test the mortar.

âWell, there was no harm done,â Riley said. âNow we know the gun is readyâwe and everybody for five miles around!â

Reassured, the crowd dispersed. Sergeant Tilton remained near the mortar, talking with a few men. The Hardys moved closer to get a better look at the old sergeant and the equipment he had been using.

Bowden also edged forward and stared with keen interest at the various markings on the gun. He told the boys that this was a Federal artillery piece.

âIt was cast at the same arsenal that turned out the famous Dictator,â he said. âThat was a thirteen-inch mortar used against Petersburg, Virginia, in the Civil War.â

Tilton raised his eyebrows in surprise. âLand sakes,â he remarked, âyou know a lot! I didnât never suspect anything like that about this olâ hunk oâ iron.â

As the sergeant began to clean the barrel of the weapon, Bowden turned to Frank and Joe. âMy offer to you,â he said in a low voice, âis one thousand dollars if you find the Spanish cannon.â

The Hardys were amazed. A thousand dollars for an old gun to be used in a pageant! I

Sensing their thoughts, Bowden quickly added, âIâm a man of means and can well afford it.â

He explained that he had already combed Bayport proper. The boysâ responsibility would lie in searching the surrounding areas and nearby towns. Bowden said he was staying at the Garden Gate Motel on the state highway and could be reached there if anything developed.

âWe donât charge for our sleuthing,â Frank informed the man.

Bowden was astonished. âYouâve solved all your cases for nothing?â

Joe nodded. âIf we should help you,â he said, âit will be on that basis.â

âOkay. But believe me, Iâll make it worth your while somehow!â Then, seeing that Tilton was preparing to leave, Bowden hastily excused himself. âI have a few questions to ask this old codger. See you later.â

The Hardys drove to police headquarters to report the underwater attack. They went directly to Chief Collig, a solidly built man in his late forties. He often cooperated with them on their cases, and now listened intently to their latest adventure.

âThis is serious,â he said. âIâll notify the harbor patrol to be on the lookout for a skin diver wearing a black suit and a black swim cap with a yellow stripe around it.â

The boys thanked him and left. As they turned into Elm Street on which they lived, their conversation centered around Bowden.

âIt looks as if weâre back in business!â Joe remarked. âLetâs take on the case.â

âIâm a little worried about it,â Frank replied. âThe whole thing seems a bit phony.â He reminded Joe of the many times they had met people who had seemed to be aboveboard, but had turned out to be dishonest.

âIt would be fun looking for the cannon,â Joe insisted.

âThatâs true.â

At the rambling stone house in which they lived, the boys were greeted by their petite mother and their tall, angular Aunt Gertrude. She was Mr. Hardyâs sister, who lived with the family. When she heard about Clyde Bowdenâs offer, Aunt Gertrude exclaimed:

âA thousand dollars for finding an old piece of junk! Thereâs something underhanded about such a deal. Mark my words!â

Mrs. Hardyâs face wore a worried frown. âI wish your father were here instead of in Florida.â

âFlorida!â Joe exclaimed. âFrank, Dad could check on Bowdenâs credentials. Letâs phone him!â

Mrs. Hardy said the detective could be reached only by mail or telegram at an address in Miami. Frank immediately sent a wire by telephone.

âWe may not get an answer for several days,â Joe remarked. âI hate to wait. Why canât we make a start on Bowdenâs case? We can drop it any time we like.â

âOkay, but letâs not get in too deep until we hear from Dad.â

âIâll let Bowden know,â said Joe. He dialed the Garden Gate Motel. Bowden was not in, so Joe left a message for him. Then he turned to Frank. âHow about advertising in the newspaper for information about the demiculverin?â

âGood idea.â By telephone Frank placed an ad in the Bayport Times, which had a wide circulation even in the smaller outlying towns.

âI have another thought,â Joe said. âMaybe Aunt Gertrude can help us.â

âHow?â

âAs newly elected president of the Bayport Historical Society,â Joe said. âshe might have some information about ancient cannon in the vicinity.â

Their aunt had gone to the kitchen to prepare lunch. Frank and Joe followed and put the question to her. After a momentâs thought, Miss Hardy said, âLet me see. I know of one cannon.â

âWhere is it?â Joe asked eagerly.

âI think itâs on the back lawn of a museum in Greenville.â

âDo you know what type it is?â Frank asked.

âI believe it may be pre-Civil War,â Aunt Gertrude replied. âIt might be Spanish. Iâm not sure.â

âWeâll take a look,â said Joe.

After lunch the boys set off in their convert. ible for the Greenville Museum. It was a small building at an intersection of two roads at the edge of town. The main entrance was on one road, with a tall hedge in front of the building. Extensive grounds stretched to the rear on the side road, along which ran a high iron picket fence. Frank parked alongside the hedge, and the young detectives strode through a gate to the spacious lawn at the back.

The cannon, a long-barreled six-pounder, stood in the center of the lawn. Joe dashed across the flagstones leading to it and read the plaque fixed to the piece.

âItâs a Spanish gun!â

Frank joined him and read the inscription on the bronze plaque. It stated:

âPasavolante, meaning fast action. Made in Toledo, Spain. Often called cerbantana, after Cerberus, the fierce dog of mythology. Pasa-volante in modern Spanish means peashooter.â

âDo you suppose this could be the peashooter that Bowden is searching for and he just got the name wrong?â Joe asked.

Frank looked thoughtful. Then he said, âI doubt it. Bowden seemed sure it was a demiculverin, didnât he?â

Joe nodded. âFalse clue.â He sighed.

As the boys started back across the lawn, they noticed a tall, slender man, with a swarthy complexion, entering from a side gate. He was bare-headed and wore a black leather motorcycle jacket. He looked around as if to make sure that he was not being observed, then moved hurriedly to the gun.

Frank and Joe, casting backward glances, watched him as they continued to the roadway. The man knelt down and read the inscription on the pasavolante. Then he rose and walked to the far side of the cannon, scrutinizing it closely.

âMaybe weâre not the only ones trying to locate a demiculverin,â Joe remarked.

âYouâre right. Letâs go back and question that fellow.â

Retracing their steps, they had covered only a few feet when the man suddenly ran for the side gate by which he had entered.

âHe must be up to something,â Joe said.

The Hardys turned back and hurried to the road. The next moment they heard a motorcycle roar into action.

âI wonder if thatâs him,â Frank said.

Before Joe could comment, the swarthy stranger sped around the corner. Goggles covered his eyes, but his lips seemed to be curled up in a nasty grin. He headed directly toward the boysl

CHAPTER III

A Motorcycle Clue

As the motorcycle roared down on them, Frank and Joe leaped aside and stumbled headlong into the hedge. The driver missed them by inches!

âSorry,â he shouted as he sped off.

The boys picked themselves up. Both were angry.

âIâd like to get my hands on him!â Frank said.

âDid you see his license number?â Joe asked.

âNo,â Frank answered ruefully. âBut the motorcycle looked like a foreign make. I noticed the letter K on the rear fender.â

âIf we ever run into that fellow again, heâll have a lot of explaining to do,â said Joe. âAnd Iâd like to ask him about his interest in the old cannon, too.â

âHe certainly acted as if he didnât want anyone to know what he was doing,â said Frank.

When the boys reached home they hurried into the kitchen. Aunt Gertrude was just removing a batch of cookies from the oven. She glanced over her spectacles and exclaimed, âFrank! Youâve torn your pants!â

âHad a little accident,â he admitted and told her of the motorcyclist.

âI knew it! Hoodlums are after you two again! Well, donât say I didnât warn you.â His aunt sighed, then added to herself, âTrouble, trouble everywhere.â

âWhere else?â Frank asked.

âThe Bayport Historical Society,â Aunt Gertrude replied. âWhat would you do with a collection of swords?â

Frank raised his eyebrows. âSwords?â

âYes, cutlasses. Iâd like to keep them.â

âPlease, Aunty, start from the beginning,â Joe begged, âand tell us about it.â

Aunt Gertrude explained that the Bayport Historical Society had recently received a gift from the estate of Senator Entwistle. It included some lovely costumes dating from 1812 and a case of cutlasses.

âI argued with our members,â Aunt Gertrude went on, âbut they insist that we present the cutlasses to the museum at the state capitol.â

âToo bad,â said Frank, then asked, âIs it your job to have them shipped?â

âYes. But they are to be moved to the basement temporarily. The museum isnât ready to receive them.â

âAnd youâd like us to help you,â Joe said.

âYes. Tomorrow evening.â

âWeâll be there,â Frank assured her.

The boys went to their room and sat down to discuss the next move in locating the cannon which Bowden wanted.

âWe canât do anything today out of town,â said Frank, glancing at the radio clock between the boysâ beds. âAnother hour and itâs time for dinner.â

âThereâs something we can do,â Joe spoke up. âVisit the motorcycle shops in Bayport and find out the name of the foreign make with a K.â

âGood idea, Joe. We may even learn the identity of that fellow who nearly ran us down.â

The young detectives had better luck than they had anticipated. The first dealer they called on explained that the letter K indicated the motorcycle was a Kesselring, a German make.

âYou donât see many of them around,â he said. âBut theyâre becoming more popular.â

âDo you sell them?â Frank asked.

âNo.â

âWho does?â

âNobody in Bayport. And no one in town owns one, either.â

âDo you know where the nearest agent is located?â Frank asked.

âYes,â the dealer replied. âIn Delmoreâ155 Main Street. His name is Braun.â

âDelmore! Thatâs where the penitentiary is,â Joe remarked.

The man nodded. âBraun mostly sells bikes, but he took on the Kesselring motorcycle agency because the machines come from his native country.â

The boys thanked the dealer and rode off in their convertible.

âLetâs drive over to Delmore in the morning and talk to that agent,â Joe suggested.

âRight,â Frank agreed. âIncidentally, the main road there is still closed. The detour leads past the Entwistle place where the cutlasses came from.â

At home the boys were greeted by the aroma of fried chicken that their mother was preparing.

âYouâre just in time,â she said, smiling.

âAny word from Dad?â Frank asked.

âNo,â Mrs. Hardy replied. âBut we should hear something soon.â

Joe questioned Aunt Gertrude about the Entwistle mansion. She said it was supposed to be deserted. âA shame, too, since itâs such a beautiful place. One of our Society members hinted that there might be some valuable pieces in the house, so well hidden the executors of the estate didnât find them. He said Mr. Entwistle was a queer old duck. Thereâs even talk that tramps stay there sometimes.â

After dinner Frank and Joe decided to ride out to the Entwistle mansion and look around.

âMaybe we can find out if thereâs anything to the talk about tramps,â said Frank as they drove along the detour road toward the old estate.

âYesââ Joe began, then broke off as the noisy approach of a motorcycle reached his ears. The next moment he exclaimed, âHey, Frank! That sounds like the Kesselring!â

His brother listened intently. âYouâre right. Hope he comes this way.â

But the Hardys were disappointed when the sound of the motorcycle grew fainter.

âHe must have turned down a side road,â Joe said. âLetâs try to catch up with him.â

Frank was about to agree when both boys saw something that made them gasp.

âThat red glow in the sky!â Joe exclaimed. âItâs right where the Entwistle mansion is!â

âThe place must be on fire!â cried out Frank, stepping harder on the accelerator.

Soon they came within sight of the grounds. On a knoll stood the huge house. One wing was a mass of flames!

âWe must get the fire department here before the whole place goes up!â said Frank.

He backed the car around, and in a few minutes the boys reached a farmhouse, where they put in a call to Bayport reporting the fire.

Then they sped back to the scene of the blaze. As they got out of the car, they heard sirens wailing. Minutes later several fire engines screamed to a halt before the burning mansion. Shouts of firemen filled the air while they fought to restrict damage to the wing that was being consumed.

Finally, after a half-hour battle, the flames were quenched and the bulk of the big house stood unscathed. Chief Tally, who had been investigating the charred ruins, returned to his car. A good friend of the Hardys, he greeted the boys with a weary smile. Frank told him they had heard that articles of value might be hidden in the house.

âCould be,â the fire chief said. âWe suspect an intruder was ransacking the place and dropped a lighted cigarette.â

Joe told him of hearing a motorcyclist racing away from the vicinity of the Entwistle place, âHe might be the one who was here,â he said.

Chief Tally smiled. âYou boys are always on the job but this is the quickest Iâve ever received a clue.â

Frank then told him about the man on the Kesselring motorcycle who had nearly run them down. âThe machine we heard tonight had the same kind of roar,â he said.

âThanks for the information.â The chief nodded, then turned to speak to two firemen who would remain at the mansion, and the boys drove home.

They slept well that night, but the ringing of the telephone early the next morning awakened them. By the time Frank reached the hallway to answer it, he heard his mother talking on the extension in her bedroom. The door was open and she waved him in.

âFenton, hereâs Frank now,â she said. âYou tell him.â She turned to her son, excitement in her eyes. âThat man Bowden is a fake!â she announced.

CHAPTER IV

New Tactics

âDAD!â Frank called into the phone. âHow are you? ... Thatâs good. Whatâs this about Bowden?â

âThe man isnât known here in Tampa, Frank. And no pirate ship with a demiculverin has been entered in the Gasparilla event.â

Frank whistled. âIâve been suspicious of Bowden from the start. But you donât think we should stop looking for the cannon, do you?â

âCertainly not. Apparently thereâs a mystery connected with it thatâs worth checking into. Furthermore, Iâm working on a swindling case that Bowden may be mixed up in. I think heâs using an assumed name.â

âShall we notify the police or shadow him ourselves?â Frank asked.

Mr. Hardyâs advice was to do neither. Instead, he suggested that his sons continue to be friendly with Bowden.

âItâs the best way to get at the truth,â he said. âAnd let me know if I can be of any more help. Iâd like to speak to your mother again.â

Frank dashed back to the boysâ bedroom and told his brother the news.

Joe hopped out of bed. âFrank, this is going to be fun. We pretend to play along with Bowden, but all the time weâre trying to find out what heâs up to!â

Frank stared out the window. âIâm wondering which problem we should tackle firstâBowden or the motorcyclist.â

âLetâs combine the two in one trip. Weâll go to the motel first, then on to Delmore.â

During breakfast with Mrs. Hardy and Aunt Gertrude, the young detectives told about their plan, and as soon as they finished eating, they started for the door. Aunt Gertrude stopped them and handed Joe a book.

âYou might as well employ your time profitably while youâre riding along. Joe, read this aloud while Frank drives.â

Her nephew glanced at the book. âWhy, this is great, Aunt Gertrude ! It tells about the various types of old artillery. Where did you find it?â

âIn your fatherâs library.â She chuckled. âI thought it might give you a clue to that demiculverin youâre trying to locate.â

The boys said good-by to their mother and aunt.

âWeâll be home in time to move those cutlasses,â Frank promised.

As they drove off, Joe turned to a section on culverins and read aloud:

â âIt derives from the Latin word colubra (snake) . Culverins were highly esteemed on ac. count of their range and effectiveness of fire. Their thick walls, long bores, and heavy powder charges made them the most deadly of field-pieces.â â

âAnd Bowden is telling us he wants to mount a fieldpiece on a pirate ship!â Frank muttered,

Joe shrugged. âThatâs what heâs telling us. I wonder what he really wants the cannon for.â

Half a mile farther down the highway, Frank pulled up in front of the Garden Gate Motel. The clerk told them Bowden was in Room 15.

âThere it is!â Joe said, spotting the number. He knocked on the door. There was no answer.

âHey, this looks like a note,â Frank said, eying a paper pinned below the doorknob.

âMaybe itâs for us,â Joe suggested.

Frank read the message aloud: â âBowden! Clear out before itâs too late!â â

âWow! I Our friend has an enemy!â Joe remarked. âDo you think this will drive him away?â

Frank shook his head. âI doubt it. He wants that cannon too badly. Well, letâs go to Delmore and stop here on our way back.â

The detour they had to make took the boys past the farm of their friend Chet Morton. Chet was eighteen, roly-poly, good-natured, and loved to eat. Solving mysteries with the Hardys always gave him the jitters. Despite this, he was a loyal assistant and on more than one occasion had rescued them from dangerous predicaments.

âLetâs stop a minute,â Joe suggested, seeing Chetâs sister Iola near the swimming pool.

Frank grinned knowingly. Joe and Iola dated frequently. He pulled into the driveway. The boys got out and walked toward the pretty dark-haired girl.

âHi! she said.

âHello, there,â Joe said. âWhereâs Chet?â

Iola pointed to the pool. Their stout friend was underwater, wearing flippers and a snorkel. He traveled slowly, the snorkel moving like the periscope of a miniature submarine.

âAhoy!â Joe yelled as they ran to the waterâs edge.

Chet continued moving about like a walrus. But finally he emerged and removed the face mask and flippers.

âHi, fellows!â he called. âIâm having a hard time learning this. Canât get down deep enough.â

âWhatâs the trouble?â Joe asked. âThat extra fat you carry around make you too buoyant?â

âNow, listen here,â said Chet, âjust because I know good food when I see itââ

Then he changed the subject, telling them he was going to take lessons in skin diving from the same man who had taught the Hardys.

âSwell,â said Joe.

âI canât start, though, until I earn enough money to buy all the gear.â

âDonât let that worry you,â Frank spoke up. âIâll lend you my outfit.â

âThanks. And now bring me up to date on everything thatâs happened lately.â

The Hardys had just finished telling Chet and Iola about Bowden, the mysterious cyclist, and the skin-diving attack, when they saw a car driving in. At the wheel sat Callie Shaw, an attractive girl with blond hair and sparkling brown eyes. She was Iolaâs friend and Frankâs regular date.

Callie alighted, and after greeting everyone, said, âIâm glad youâre all here. I wanted to talk over plans for our Fourth-of-July beach party. Tony Prito is coming with us too.â

Tony, a schoolmate and fellow athlete at Bayport High, had been through many adventures with the Hardys.

âLetâs have a clambake like last year,â Chet suggested.

Suddenly Frank grabbed Joeâs arm. âLook over there! A manâs spying on us!â

He had seen someone peering from behind a tree near the road. The quick glimpse of a black jacket led Frank to believe that the man might be the wanted motorcyclist!

âCome on, Joe!â he whispered, starting to run.

Instantly the man raced off. Having the advantage of a head start, he reached a parked motorcycle, jumped on, and sped off.

From the silhouette of the rider and the sound of the motor, there was no doubt in the Hardysâ minds as to the spyâs identity.

âItâs the guy weâre looking for!â Joe exclaimed.

Together, the Hardys ran back to their car and hurried after the suspect. They had covered nearly two miles before they caught sight of him. Reaching the crest of the next slope, he looked back. Seeing that his pursuers were getting closer, he revved his machine and shot into the curving downgrade.

âFaster!â Joe urged. âHeâs getting away from us!â

Their car whined around the curve in hot pursuit of the Kesselring. Once again they came to a straight stretch of road, but there was no sign of the motorcyclist.

âHe turned off!â Joe said in disappointment.

âHe must have swung into that dirt road we just passed. Letâs go back!â Frank exclaimed.

Screeching to a stop, he made a U-turn and sped to the side road. They plunged onto the rough, narrow, dirt lane. Fresh motorcycle marks were clearly evident. Dust filled the air, choking the boys as they sped along.

âStop!â Joe cried suddenly. âThe track ends here!â

Frank parked the car and locked it, then both boys ran back to the point where the tracks turned off into the pine woods.

âHe couldnât go very far through here on his motorcycle,â Frank said as they pressed on excitedly.

âYouâre right!â Joe whispered. âLook!â

CHAPTER V

The Stakeout

AHEAD of the Hardys in the deep woods stood a cabin. The Kesselring was parked near the front door.

Quietly the boys moved into a position giving them a better view of the building.

âShall we go in?â Joe asked in a low voice.

âIâll go,â Frank replied. âYou cover the rear, okay?â

âRoger.â

Frank walked cautiously toward the front door. It was open and the place appeared to be deserted. The young detective strode inside. No one was in sight!

Frank went out and joined Joe. âHe gave us the slip!â he said in disgust.

âBut not for long. Heâll be back for his bike,â Joe said. He suggested that they pretend to leave, then double back and stay in hiding until the man returned.

âSuppose he finds out our car is still on the road,â Frank said.

âWeâll have to take that chance,â Joe declared.

The boys walked off in the direction of their convertible, but five hundred feet beyond the cabin they turned and quietly made their way back. Hiding behind clumps of brush, they began their vigil. Fifteen minutes went by. Thirty.

Suddenly the quiet of the morning was broken by the crackling sound of footsteps.

The Hardys tensed. Someone was approaching from behind them. They shifted their position.

âGet ready, Joe,â Frank whispered.

The steps grew louder and a tall figure appeared through the brush. The boys pounced on the newcomer and all three fell hard to the ground.

âBowden!â Joe gasped.

âFor heavenâs sake, what ails you guys?â the man stormed, picking himself up.

âWe thought you were someone else,â Joe replied.

âWhy are you here?â Frank asked, wondering if Bowden had a rendezvous with the occupant of the cabin.

âI might ask you the same thing,â Bowden retorted.

The boys pounced on the newcomer

âThatâs easily answered,â Frank said, pointing to the motorcycle. âWe want to talk to the man who owns it.â

âDo you know him?â Joe asked Bowden.

âNever saw the thing before,â he answered.

âNow tell us what brings you here,â Frank went on.

âA tip about the demiculverin.â Bowden glanced about apprehensively. âIt may be buried near here.â

Both boys surmised this was another phony story. Bowden was carrying no digging tools, nor was he dressed in work clothes.

âWho gave you the tip?â Frank asked.

âI canât tell you that. The information was given to me in confidence.â

Frank was tempted to ask Bowden why he wanted a fieldpiece for a ship. But recalling his fatherâs admonition to play along with the suspect, he merely said:

âSorry we knocked you down, Mr. Bowden. Let us know if you want us to help dig here.â

Joe followed Frankâs cue to be pleasant. âWe went to the motel to see you this morning,â he said. âFrank and I thought weâd talk to you a little more about the cannon you want us to find.â

Frank broke in. âWe saw the warning note on your door.â He watched Bowden closely.

âWarning note?â the man repeated, showing real surprise. After Frank explained, Bowden suddenly laughed. âI guess those kids at the motel were pulling a joke on me. They were playing cops-and-robbers when I left.â He glanced at his wrist watch. âI must get back.â

He strode off in the direction of the road. Joe turned to Frank. âDo you believe that cops-and-robbers story?â

âNo. I didnât see any children around that motel. You know, one of us ought to follow Bowden and send the police up here.â

âGood idea,â Joe said. âYou go; Iâll stay.â

While he concealed himself to stake out the cabin, Frank cautiously tailed the suspect. âIâll bet we interrupted some kind of meeting,â he said to himself.

Bowden walked toward a green Pontiac hardtop parked on the road and roared off. Frank followed in the convertible, memorizing the Pontiacâs license number. He was disappointed when the man drove directly to his motel, took the note off his door, and went into his cabin. When he had not come out fifteen minutes later, Frank decided to call Chief Collig and drove to a gas station.

The police chief agreed to send two men to the woods and Frank returned to the spot where he had left his brother.

âAnything doing?â he asked when he arrived at Joeâs hideout.

Joe shook his head and Frank told him about Bowden and Chief Collig. Ten minutes later the boys were relieved by two plainclothesmen.

The Hardys hurried through the woods and drove on to Delmore. It was nearly noon when they arrived at the motorcycle shop.

âGood morning,â said the short, smiling proprietor, who introduced himself as Mr. Braun.

âWeâre interested in Kesselrings,â Frank replied. âDo you sell them?â

âYes, I have the agency. But I havenât sold any motorcycles in a long time. Oneâs been standing in my basement for weeks.â

Frank and Joe looked at each other. Was their clue going to lead nowhere?

Joe said, âWeâd like to see it.â

The three descended a flight of wooden stairs. The man walked around a high pile of cartons, then suddenly exclaimed:

âMy Kesselring! Itâs gone! Stolen!â

Mr. Braun excitedly went on to say that he had been away on vacation for two weeks and had just returned. The Kesselring had been there when he left.

âAch, what will I do?â he wailed.

Frank laid a hand on his shoulder.

âYou may get it back this very day,â he said. He told of finding the motorcycle at the cabin and of the policemen now at the spot waiting to capture the thief. The dealer was overjoyed.

Frank at once telephoned this latest development to Chief Collig, while Mr. Braun thanked the boys repeatedly. Then they said good-by and left. After a quick lunch at a nearby diner they returned to their convertible.

âJoe, I have a hunch,â said Frank. âThat motorcycle thief might be a recently released in. mate of the penitentiary. Mr. Braunâs shop here in Delmore would be a likely place for him to rob. Letâs call on Warden Duckworth and ask him some questions.â

âGood idea.â

The warden was an old friend of Mr. Hardy, and the boys had once assisted him in solving a prison break. Reaching the penitentiary, Frank called him from the main gate phone. A guard accompanied them to Warden Duckworthâs office, where the official greeted them cordially.

âWhat brings you way out here from Bayport?â

Frank told him their suspicions and said, âWeâd like to find out the names of men released from here within the past two weeks.â

Warden Duckworth rose, walked to his filing cabinet, checked the records, and returned with some cards. âWeâve let six men go,â he replied. âFour old-timers and a couple of young fellows.â

âThe man we suspect is probably in his twenties,â Frank said. âWho were the young ones?â

âOne is Bob Chidsie, a car thief. The other, Hal Latsky, a safecracker.â

âMay we see their pictures?â Frank asked.

âCertainly.â Duckworth handed over the record cards, to which small photos were attached.

âThat looks like the motorcycle thief!â Joe said immediately, pointing to Latsky.

Frank was thoughtful. âDonât forget, Joe, weâve never seen this fellow close up without his goggles. Warden, could you tell us something more about him?â

âYesââ The man studied Latskyâs card for a moment. âBesides being a safecracker, heâs an explosives expert. Also, he has an unusual hobbyâthe study of ancient cannon!â

CHAPTER VI

Mysterious Attackers

AT the mention of Latskyâs interest in old cannons, Frank cried out, âThat convinces me, Warden! Latsky must be the man weâre after!â

Once more the Hardys telephoned Chief Collig, who was amazed by the latest development in the boysâ sleuthing. âAre you sure you donât want to join the force?â he asked with a chuckle.

Then he gave them a report on the stakeout in the woods. âBraun phoned in the serial number of the stolen Kesselring,â he said, âand our men at the cabin made a positive identification. Itâs Braunâs bike all right. The thief hasnât returned yet, but weâll maintain a round-the-clock surveillance for as long as we need it. Braun has agreed to leave the motorcycle there as bait for the thief. He might try to get it back.â

Before the Hardys left, Warden Duckworth handed them pictures of Latsky. âGive these to Chief Collig,â he requested.

On the way to Bayport the boys discussed the strange turn of events. Was Latsky trailing the Hardys because they were searching for an old cannon? Did he know Bowden, and had the two planned a meeting in the woods? Or were they enemies, both looking for the old demiculverin?

âIâm going to phone Warden Duckworth and see if he can tell us anything about Bowden,â said Frank.

When the boys reached home, Frank immediately made the call. The warden said he had no released prisoner on his list named Bowden, nor had he ever heard Latsky mention anyone by that name.

âIâll ask the guards and prisoners, though,â Warden Duckworth promised. An hour later he called back. âIf Latsky knows anyone named Bowden, he never mentioned it here.â

âThanks, anyway,â said Frank and hung up.

He was disappointed not to have uncovered another clue but turned his attention to Aunt Gertrude, who had just come in the front door. She was waving three letters.

âI picked these up from the box at the newspaper office,â she said, handing them over. âYou forgot all about your ad. I suppose these are some answers. Well, hurry up and open them. Iâm entitled to know whatâs inside!â

Frank smiled as he tore open the first envelope. Joe came to stand beside him, and read the letter over his brotherâs shoulder.

The writer proved to be the amusing old artillery sergeant who had set off the mortar in the town square the previous day. Sergeant Tilton said that he lived up the coast near Piratesâ Hill. He had once heard there was an old cannon on the hill, but it had been buried by sand in a storm many years agoâlong before Tiltonâs birth.

Both boys agreed that the lead should be investigated.

The second letter was from Mr. Maglan, the retired custodian of the Bayport Historical Society. Frank opened it.

âWait till you hear this, Aunty.â He chuckled.

âWhy, what is it?â

âMr. Maglan says three old cannons have been stored in the cellar of the Historical Societyâs building for thirty years!â

âWhat!â exclaimed Miss Hardy. âCannons in the basement!â

Joe roared with laughter. âWhy, Aunt Gertrude, I always thought you knew everything about the Bayport Historical Society building.â

The boysâ aunt did not laugh. âThis is serious. Suppose there is powder in those guns!â she cried out. âWhyââ

Frank assured her that thirty-year-old gun-powder would be damp and harmless. Aunt Gertrude merely said âHumph!â and then reminded her nephews tartly about carrying the cutlasses to the basement. âMr. Lightbody says theyâre in the way.â

âWeâll go right after dinner,â Joe said. âAnd weâll investigate those old cannons at the same time.â

The third note was of more serious import. Letters of the alphabet had been cut from newspapers and pasted on the paper to form words. The message bore no signature. It read:

LOOK fOR THE CANNON AT YOUR OWN RISK. IF YOUâRE SMART YOUâLL DROP .BOWDENâS CASE.

âWow! Things are really getting complicated!â Joe exclaimed.

âYes,â Frank agreed. âAnd the writer must have found out weâre the ones who put that ad in the paper.â

âI donât like this!â Aunt Gertrude declared.

When Mrs. Hardy heard about the threat, she too became alarmed. Both she and Aunt Gertrude appealed to the boys to drop the case, at least until their father returned from Florida.

âWe canât stop work now,â Frank objected. âJoe and I are just getting some good leads. And anywayââ

The ringing of the telephone interrupted his protest. As Joe picked up the phone, everyone waited tensely.

âMaybe itâs your father,â Mrs. Hardy whispered.

Frank noticed Joeâs jaws tighten as he listened. It could not be a call from their father.

âFrank,â Joe whispered, âcome here! Itâs Bowden. He wants to talk to you, too.â

His brother put his ear close to the phone âHello,â he said, âthis is Frank.â

Bowdenâs voice sounded scared. âListen! Youâve got to help me! Iâve been threatened!â

âBy whom?â Frank asked. âThose kids again?â

âNo, no. This is for real!â Bowdenâs voice was shaky and faint. But suddenly it became strong again. âFr-ank! Joe!â he cried out.

âWere you threatened by someone named Latsky?â Frank demanded.

There was no answer.

âMr. Bowden?â Frank said questioningly.

Still there was no response, but suddenly the Hardys heard a thud and the noise of a phone dropping onto a hard surface.

âHello! Hello!â Frank kept saying.

There was dead silence for another moment. Then a strange voice said ominously into the instrument:

âYou Hardy boys! Drop the cannon search at once! This is your last warning!â

The threat ended with a sharp dick as the intruder in Bowdenâs room slammed down the telephone.

Frank whirled to face his brother. âIt sounds as if Bowden had been attacked! Probably by the person who just gave us that final warning!â

Joe started for the door. âLetâs hurry over to Bowdenâs motel. We may catch the guy.â

Frank thought it best to get help to Bowden immediately. âHe may be seriously injured. Iâll notify the desk clerk at the Garden Gate.â

With frantic haste, Frank dialed the motel office number, but the line was busy.

âCome on!â Joe urged impatiently. âWe can get there in a few minutes if we hurry.â

The boys ran to the convertible. When they reached the motel, Frank pulled up in front of Room 15. The door stood ajar and they burst inside.

Bowden lay face down on the floor, unconscious. Blood trickled from the back of his head!

As Joe and Frank rushed over to him, the man groaned slightly and moved his arms. Frank turned him over.

âIâll get some water,â Joe offered, and hurried to the bathroom for it. He soaked a towel in cold water and pressed it against the manâs neck and face. Bowden shook his head dazedly as he regained consciousness, and the boys helped him to his feet.

âHow did youâ?â he stammered, recognizing them. âWhereâsâ? ... Oh, my head!â

Frank assisted Bowden to the bed, where Joe applied an antiseptic bandage he had found in the bathroom medicine chest. Then they began to question him. Bowden said he had not seen his attacker.

âI hadnât locked my door,â he explained. âSomebody must have sneaked up from behind and hit me!â

âLatsky?â Frank queried, watching Bowden intently.

âWhoâs he? Never heard of him,â the man said.

âWho threatened you?â Joe asked.

âI donât know. An unsigned note had been shoved under my door. Itâs rightââ Bowden looked toward the telephone table. âWhyâitâs gone! It was right there!â

âYour attacker must have taken it,â Joe said. âWhat happened to the other note that was stuck on your door?â

âI threw it out. Thought the kids around here were playing a joke on me. Now it looks as if I could have been wrong.â

Frank telephoned the desk and reported the assault. The clerk said he had not seen anyone suspicious and promised to notify the police at once.

When Bowdenâs condition improved, the Hardys tried to ferret out more information from their mysterious client. âWhere did you say you live in Tampa?â Joe inquired.

âI didnât say. Why do you ask?â

Joe explained that he thought Bowdenâs family should be notified in case of serious trouble.

âForget it,â Bowden replied with a wave of the hand. âI havenât any family.â

The manâs reluctance to tell where he lived seemed to confirm Mr. Hardyâs suspicion that Bowden might be mixed up with a group of swindlers.

âAbout the demiculverin,â Frank went on. âI read that itâs a fieldpiece and not used on ships.â

Bowden was startled for a moment but regained his composure by pulling out a cigar. Lighting it, he said, âI admire your thoroughness. But I didnât want the cannon for a ship, only for a pageantâas part of the shore batteries.â

âOh,â Frank said nonchalantly, âthen the demiculverin isnât too important.â

âWhat?â

âIf itâs just for a dummy shore battery, you can rig up a wooden one,â Frank added.

âButâbut, boys!â Bowdenâs face grew red with excitement. âI must have the old cannon. Everything has to be authentic.â

He laid a firm hand on Frankâs arm. âYouâve got to help me! Iâll double the reward. How about two thousand dollars?â

âItâs not the money, Mr. Bowden,â Frank replied. âItâs just thatââ

âAll right, Iâll cooperate better,â he said pleadingly.

âFor example?â

âI canât reveal all my secrets, but I feel certain the cannon will be found along the shore here.â

âWeâll do our best,â Frank promised.

When the police arrived, the boys told them all they knew about the attack on Bowden but said nothing about the threat to themselves. Then they left.

âWhat do you make of it?â Joe asked his brother as they drove away from the motel.

âThis mystery is getting more complicated by the minute,â Frank replied. âBowden has an enemy all right, and heâs lying when he says he doesnât know who he is.â

On the way home the boys noticed another convertible following them. In the rear-view mirror Frank saw that the driver was a good-looking young man in his twenties. He was alone.

âDo you think heâs trailing us?â Frank asked.

The car had remained fifty feet behind the Hardysâ for about half a mile.

âWhy donât you find out? Slow down and see if heâll pass,â Joe suggested.

Frank did so. The other driver pulled out and zoomed ahead, staring intently at the Hardys as he passed them.

âDid you recognize him, Frank?â

âNever saw him before.â

When they arrived home Aunt Gertrude told them that the Historical Society had just decided to hold a special meeting that evening. âYou can drive me over, then move the cutlasses to the basement,â she said.

After supper Frank and Joe accompanied Miss Hardy to the Historical Society building. When they pulled into the parking lot in the rear of the old stone building, several members were going in the front entrance.

As Miss Hardy alighted she pointed to a basement window which was open. âSuch carelessness!â she sputtered. âI must speak to Mr. Lightbody. FrankâJoe, please close it and lock it when youâre down there. Humph! The whole place will be full of stray cats!â

Her nephews grinned as they followed their aunt to the front of the building and went inside.

âThe cutlasses are at the rear of that corridor,â Aunt Gertrude said, pointing. âCarry them downstairs and donât disturb our meeting!â

Then she walked briskly into the auditorium.

Frank and Joe went down the corridor. At the end of it stood a case with the six cutlasses from the Entwistle estate. Joe lifted out two of the short swords and examined them.

âBoy, the real thing!â he remarked in a low voice. âTheyâre heavy. And look at this edge, Frank.â Taking an old envelope from his pocket he sliced it in half with an effortless motion.

âIâd say these are more dangerous than the cannon,â Frank murmured. âMaybe thatâs why some of the Society members donât want them on exhibit here.â

âHow about a look at the heavy artillery?â Joe said as the boys replaced the cutlasses in the case.

They looked about for the custodian to show them the basement entrance, but could not locate him.

âI guess we can find our way,â Frank said.

He walked over to a door and pulled it gingerly. Instead of leading to the basement, it opened into the auditorium.

Aunt Gertrude was on the dais, gavel in hand. âThe meeting will come to order,â she said with authority, and the ensuing bang made it plain that she meant every word.

As the members quieted, Frank saw the custodian seated in the front row. He was a small, thin man with gray hair and a wispy mustache. The boys decided not to bother him.

âLetâs try this door,â Joe said, walking across the corridor. He turned the knob. The door yawned open into pitch blackness.

âThis is the basement entrance, all right.â He reached inside for the light switch and flicked it on. Nothing happened.

âI guess the bulbâs burned out,â Joe said. âIâll get a light from the car, Frank.â

He hurried outside and brought back a flashlight which the boys carried with them at all times. As he beamed it down the steps, Frank lifted the case of cutlasses to his shoulders.

âLead the way, Joe.â

Joe went slowly down the cellar steps.

âCareful,â he warned. âTheyâre steep.â

The next moment he pitched forward. A blow on the side of his head had knocked him unconscious!

âJoe, what happened?â Frank cried as the flashlight flew forward and rolled under a table.

In the feeble glow Frank missed his footing and lost his balance. The case of swords fell from his shoulder and landed with a jangling crash. Frank banged his head on the case and blacked out.

His outcry and the crash of the case threw the Historical Society meeting into an uproar. Mr. Lightbody jumped to his feet.

At the same time Aunt Gertrude pounded her gavel for order. âKeep calm. Iâll find out whatâs wrong downstairs. Come, Mr. Lightbody. Vice-President, please take the chair!â

Miss Hardy charged to the basement door ahead of the custodian and groped her way down the steps. âFrank! Joe!â she called.

She found the flashlight, which was still beaming. Waving it around, she gasped.

Dashing for the open window was a man in a motorcycle jacket, a mask over his face.

In his arms were five cutlasses, which had been hurled from the case. The sixth lay on the floor, next to the motionless Hardys.

Quickly sizing up the situation, Aunt Gertrude reached down for the sword, at the same time crying, âYou scoundrel! What have you done to my nephews?â

With a flailing motion, she slapped the manâs back with the broad side of the cutlass. He shoved her back.

âOh, no, you donât!â she cried out.

Thwack! She hit him again. Terrified, the burglar dropped the five cutlasses and leaped to the sill. As he started to crawl through the window, Aunt Gertrude whacked him again!

CHAPTER VII

The Battle of Bayport

THE next moment the intruder was gone. Miss Hardy turned her attention to Frank and Joe.

âWhereâs the electrical panel, Mr. Lightbody?â she asked.

âUnder the stairs.â He found it and reported that the basement switch had been pulled, probably by the intruder. The custodian flicked the handle up and the place was flooded with light.

âWhat happened?â someone called out from the top of the stairs. âDo you need help?â

âPhone the police,â said Miss Hardy as she began to chafe her nephewsâ wrists and the backs of their necks. They soon regained consciousness.

The only injuries the boys had sustained were bruises on their heads. Joe surmised that he had been hit with a blackjack.

After Aunt Gertrude had given a brief description of the assailant, Frank said tersely, âSounds like Latsky. Letâs check for clues to make sure.â

As they searched, Mr. Lightbody said the basement windows were always locked. The intruder must have forced one open.

When Chief Collig arrived, Aunt Gertrude told him the story of the attempted theft. âFrank and Joe think it was Latsky,â she concluded.

The officer agreed. But a search outside failed to reveal any clues.

The Hardys were still looking in the basement for clues when Chief Collig came downstairs. Suddenly Frank said, âHey, hereâs a button from the fellowâs jacket!â On the floor near the open window lay a triangular black button imprinted with a motorcycle wheel!

Collig dropped the button into his coat pocket and said, âThe motorcycle rider hasnât come back to the cabin yet, but Iâm hoping heâll show up soon.â

After the chief had left, Joe turned to his aunt. âWe havenât thanked you for saving us from further damage.â

âOh, well, somebody had to look after you!â she said, going out the door. âMr. Lightbody, lock and bar the window. Boys, take those cutlasses. Letâs see, where will they be safe? Thereâs a closet upstairs. Weâll lock them in there for the time being.â

When Mr. Lightbody and the boys climbed upstairs a few minutes later and put away the swords, they found Aunt Gertrude surrounded by members of the Society, praising her for her winning the âBattle of Bayport.â

âIt was nothing,â she insisted. âNow weâll resume the meeting.â

All the members followed her into the auditorium except Mr. Lightbody. âI can tell you about a real Battle of Bayport,â he said to Frank and Joe.

He explained that in reading pirate lore, he had learned that in 1756 a buccaneer ship had attacked two armed merchantmen off Bayport. One of the trading vessels had been sunk with all the officers and crew lost. The other merchantman had managed to sail away.

âThe pirate ship,â Mr. Lightbody continued, âhad had so much of her sail raked by the cannon of the merchantmen that she was unable to give chase. Instead, for some unknown reason, she sent a landing party ashore. Some time later the party returned aboard and the pirate ship limped off.â

âWhere did this happen?â Joe asked.

âOff Piratesâ Hill,â Mr. Lightbody replied. âThe hill is really named after that incident.â

Frank and Joe eyed each other. Maybe this was the basis for Jim Tiltonâs account of the cannon buried in the sand!

âThatâs quite a story,â said Frank. âAnd now weâd like to see the old cannons in the basement.â

Mr. Lightbody led the way down another stairway and unlocked a door to a dusty, vaultlike room. Three old weapons, green with age, were set up in a row on oak mounts.

âAll three are British pieces,â the custodian said. âTheyâre a minion, a saker, and a pedrero. And theyâre all made of cast bronze.â

âWhat interesting names!â Joe exclaimed.

âThe saker was named after the saker hawk, one of the fiercer birds used in falconry. The pedreroâyouâll notice that itâs longer than the othersâIs relatively lighter because it was used to hurl stone projectiles. The minion is the smallest.â

âThey have beautiful decorations,â Frank observed.

The pieces were covered with flower-and-leaf designs. Atop the saker, at its balance point, was a handle in the shape of a dolphin.

âThis handle,â Mr. Lightbody explained, âwas used for lashing or lifting the piece. And cannon like these often had colorful nicknames set in raised letters on the barrel.â

âThis first one is marked Wasp,â Joe commented. âThe other cannons have no names on them.â

The boys studied them for a while, then Mr. Lightbody locked the door and led the way upstairs. Reaching the hall, Frank whispered to Joe, âThat clue to the demiculverin petered out. Letâs try Piratesâ Hill next.â

âRight. Weâll go there tomorrow.â

Just then Aunt Gertrude, followed by the other Society members, came from the meeting room. The boysâ aunt was beaming.

âThe Society has just voted to present us Hardys with one of the cutlasses,â she told them.

Frank and Joe grinned in delight, âGreat!â said Frank, and Joe added, âItâll be a swell souvenir of the Battle of Bayport! Letâs take the one you used to scare off the thief!â

He and Mr. Lightbody went to the closet to get it.

The Hardys returned home directly and Joe made a rack for the prized cutlass. Frank hung the weapon on the stairway wall.

âLooks good,â Joe remarked. âI think Dad will like it.â

As the boys prepared for bed, they speculated about the masked thiefâs reason for wanting the cutlasses. But they could come to no conclusion and finally they fell asleep.

Next morning after breakfast the boys made plans for their trip to Piratesâ Hill.

âBowden seemed pretty sure the demiculverinâs somewhere around there,â Frank mused. âLetâs try to get a little more information from him before we leave.â

He went to the phone and called the Garden Gate Motel.

âBad news,â he said, returning to Joe. âBowden checked out early this morning!â

Joe stared at his brother. Then he asked, âFlorida?â

âHe left no forwarding address. Bowden must really be scared of somebody.â

Frank and Joe decided to postpone their trip to Piratesâ Hill and look for Bowden instead. They would go the rounds of local gas stations, hoping to find that the man had stopped at one and might have mentioned his destination.

They visited one after another without result. As they were about to return home, Joe said:

âFrank, thereâs a gas station about two miles out of town on Route 7. Maybe Bowden stopped there.â

They headed for the place and a few minutes later pulled in. A boy was in attendance.

âSay,â Frank said to him, âdid a man stop here this morning in a green Pontiac hardtop?â

âYes,â the attendant replied.

âWas he about thirty-five years old, stocky build, and did he have wiry black hair?

âYes.â

Frank said they were trying to find him and wondered where he had gone.

âSaid he had a business deal in Taylorville.â

Elated, the Hardys grinned broadly and thanked the boy.

âI hope we can make Taylorville before Bowden pulls out of there too,â Frank said.

He kept the convertible at a steady pace and they reached Taylorville at twelve oâclock. The town was a fair-sized one, and the streets swarmed with cars and people during the lunch-hour rush.

The boys began a systematic search for Bowdenâs car, going up one street and down another. After they had exhausted the business area, they started on the residential section.

âI see it!â Frank cried out presently.

Bowdenâs green hardtop was parked in front of an old-fashioned house which advertised that luncheons and dinners were served there.

âMaybe heâs eating,â Joe remarked. âLetâs park our car around the corner so he wonât spot it.â

Frank agreed this was a good idea and kept going. He pulled into a secluded, dead-end street and locked the convertible. As they walked back toward the restaurant, Frank suddenly grabbed his brotherâs arm. âWeâd better duck. Here he comes!â

âWhere?â Joe asked.

âFrom that house down the streetâthe big white one.â

They stepped in back of a hedge and watched the suspect. He went directly toward his car but did not get in. Instead, he turned into the walk which led to the restaurant and disappeared inside.

âWhat a break!â said Frank. âJoe, you watch the restaurant. Iâll go over to that big white house and see if I can find out what Bowden was doing there.â

Fortunately the restaurant was almost completely screened from the street by tall trees and shrubbery. There was little chance of Bowden seeing the Hardys.

âYou canât just walk into that house and ask about him,â Joe said. âSuppose whoever lives there is in league with him?â

âIâll have to do a little acting,â Frank agreed. âPose as a salesman, for instance, and just try to get a conversation going.â

âOkay. Now whatâll I do if Bowden suddenly comes out?â

âRun for our car and give two blasts on the horn. Iâll come over right away so we can follow him.â

Frank hurried across the street and rang the bell of the big white house, planning his strategy as he waited.

A thin, white-haired man answered the door. Smiling, Frank inquired if he were Mr. Chestnut. When the man shook his head, Frank asked if he knew where Mr. Chestnut lived.

âNever heard of anybody by that name around here,â the elderly man said. He chuckled. âBut you came close, son. My nameâs a tree one, too, Itâs Ash.â

Frank laughed. Then he said, âIâm Frank Harber from the Nationwide Insurance Company. You see, we are introducing a new medical plan and Mr. Chestnut had inquired about it. The girl on our switchboard must have gotten the address wrong. Anyway, since Iâm here, would you like to hear some more about it yourself?â

Mr. Ash smiled. âSorry, but Iâm already covered sufficiently. Besides, I just spent all my money. A salesman was here a few minutes ago and sold me some stock.â

Frankâs heart leaped. He was learning more than he had bargained for!

CHAPTER VIII

Spies

WITHOUT seeming to be too inquisitive, Frank asked Mr. Ash, âWas it oil stock you bought?â

The elderly man shook his head. âIt was mining stock. The Copper Slope Mining Company. Ever hear of it?â

Frank said he had and in fact his father owned some.

âIâll bet Dad will be surprised to hear what Bowden is selling,â Frank thought, then said aloud, âWhere could I find the salesman if I should want to buy some stock?â

Mr. Ash told him the manâs name was Bowden and he was staying at the Garden Gate Motel in Bayport. âThatâs where he told me to phone him if I wanted more.â

Frank was so amazed that he almost blurted out the fact that Bowden was no longer at the Garden Gate Motel. He thanked Mr. Ash for his courtesy, then walked quickly down the street. Joining his brother, he told him what he had learned. Joe was equally amazed and puzzled. Though the stock was high grade, Bowdenâs method of transacting business seemed strange. Both boys surmised that the stock certificate he had given Mr Ash was probably a phony one.

âWeâll wait for Bowden and trail him,â Frank stated.

It was not long before the suspect came out of the restaurant and got into his car. Frank and Joe dashed around the corner and hopped into their convertible. The trail led toward Bayport, and when they reached the outskirts, Bowden not only turned into the Garden Gate Motel, but went to Room 15, unlocked it, and stepped inside.

âWell, can you beat that!â Joe said.

The boys parked and went into the office to speak to the clerk who had given Frank the information about Bowdenâs leaving. The man looked surprised.

âI thought you said Mr. Borden on the phone,â he explained. âSorry. Mr. Bowden is still in Room 15.â

The boys went to see him and held a casual conversation about Piratesâ Hill, saying they were going to start searching that area. Frank asked Bowden if he had any suggestions for them.

âNo, I havenât,â he replied. âBut Iâm glad to hear youâre going to start work. I donât know how long I can wait around here.â

âAre you thinking of leaving soon?â Joe asked casually, hoping for information.

âOh, not right away,â Bowden answered. âBut staying here to locate that demiculverin is taking a lot of my valuable time.â

âI understand,â said Frank. âWell, weâll let you know what we find out.â

Since it was too late to search on Piratesâ Hill that day, the boys went home. They gathered the various tools which they would use for their digging and put them in the convertible.

âWeâll have to take time out from the beach party tomorrow to make a search,â said Frank.

Shortly after breakfast the next morning the phone rang. Frank answered the call. It was from Mr. Lightbody. In a highly excited voice the curator cried out:

âThe Historical Society building was broken into late last night, and the cutlasses have been stolen!â

âStolen!â Frank exclaimed. âHow did the thief get in? Didnât you secure all the windows?â

âYes, of course. This time a rear door of the building was forced.â

âJoe and I will be right over,â said Frank.

The entire family was upset by the news. Aunt Gertrude declared that she was going along.

âI feel a personal responsibility for those cutlasses,â she said.

Miss Hardy and the boys set off at once. By the time they reached the Historical Society building, Chief Collig was there.

âThis certainly is unfortunate,â he said. âI canât understand how that thief got in here so easily.â

âDonât forget, Latsky is a safecracker,â Joe reminded the chief.

âWait a second,â Frank said. âLetâs not jump to conclusions. We donât know for certain that it was Latsky who broke in here the second time.â

Chief Collig agreed with Frankâs reasoning. He said he would put extra men on the case and notify the State Police to be on the lookout for Latsky.

âNeither he nor anyone else has shown up at the cabin in the woods,â the officer reported. âI believe the fellow knows weâre watching the place and wonât return.â

At that moment there was a loud booming of the old mortar in the town square. Frank and Joe looked at each other and smiled. They had completely forgotten that it was Independence Day! They had planned to watch the parade, then start off for the beach party.

It was eleven oâclock when they leached home. Joe carried the food to the car while Frank consulted a book on tides in the Bayport area. Coming out to Joe, he said:

âI guess we canât take the Sleuth after all. The water will be too shallow near Piratesâ Hill. It will be low tide in the middle of the day.â

âHow about asking Tony if we can go in his Napoli?â Joe suggested. âIt draws much less water than the Sleuth.â

âGood idea, Joe. Iâll call him.â He went to the phone.

âSure, we can use the Napoli,â Tony said. âIâll meet you at the dock.â

The Hardys drove off, heading first for the Morton farm. Chet and Iola were waiting for them, with several baskets of food which included lobsters and a sack of clams. Their next stop was at the Shaw house to pick up Callie, then they drove directly to the waterfront.

âHi!â cried Tony, giving his friends an expansive grin. The Napoli was chugging quietly at her berth.

After the food and digging tools had been transferred to the craft and the Hardys had brought their diving gear from the Sleuth, everyone stepped aboard and Tony shoved off.

When they reached the end of the bay and turned up the coast, the young people watched for Piratesâ Hill. Minutes later they saw it in the distance. The hill was a desolate hump of sand-covered stone jutting into the sea. There was not a house in sight, except one small cottage about half a mile beyond the crown of the hill.

âThat must be Sergeant Tiltonâs place,â Frank remarked.

Tony slowed down the Napoli some distance off shore and said he was going to test the depth with a pole before going any closer toward land.

âSay, how about my trying out the diving gear now?â Chet asked.

âYou can use mine,â Frank replied. âIâll help you adjust the equipment.â

âI think Iâll put my gear on, too, in case Chet runs into trouble,â said Joe.

He quickly strapped his air tanks into position and the two boys stepped to the gunwale.

âHold it!â said Tony. âA guy in a motorboat over there is waving at us frantically. Wonder whatâs up.â

âWho is he?â Frank asked.

âIâve never seen the fellow before,â Tony replied as the boat hove alongside.

Frank called out to the newcomer, a fisherman about fifty, and asked him what was wrong.

âIâm glad I got to you folks in time,â the stranger replied. He spoke excitedly. âI just spotted a giant sting ray near here while I was fishing.â

âA sting ray!â Frank echoed in surprise. âWell, thanks for telling us. Weâll stay out of the water.â

Tony pulled a pole from the bottom of the motorboat and asked Frank to test the depth from the prow of the Napoli. Then slowly he steered the boat shoreward.

All this time Joe had been casting his eyes over the large expanse of water. There was no sign of the sting ray. Finally he said aloud:

âDo you suppose that man was trying to scare us away from here?â

âWhat do you mean?â asked Callie.

âWell, a lot of funny things have been going on lately,â said Joe. âIt wouldnât surprise me if that fellow had some reason for not wanting us to go into the water.â

He found binoculars in a compartment and trained them on the other boat which by now was a good distance away. The craft lacked both a name and Coast Guard identification number.

âThat fisherman isnât alone!â Joe exclaimed. âI just saw another manâs head pop out from under the tarpaulin!â

âCan you see his face?â Frank asked.

âNo. Heâs getting up now, but his backâs turned to us.â

âLetâs find out who those two men are!â Joe urged.

Tony revved up the motor and the Napoli skimmed across the water. Joe kept the binoculars trained on the mysterious fisherman. Suddenly they seemed to realize that the young people were heading directly toward them. Like a flash the man who had remained hidden before dived under the tarpaulin in the bottom of the boat.

The other man started the engine. Then, in a roar which carried across the waves, the boat raced off.

âWow!â Chet exclaimed. âSome speedy craft!â

âIâll say it is!â said Frank. âThatâs no ordinary fishing boat!â

The Napoli was fast but not fast enough to overtake the other boat. After a chase of a mile, their quarry was out of sight. Tony turned back to Piratesâ Hill.

The boys continued to discuss the menâs strange actions until they were almost ashore. Then Chet said, âLetâs forget the mystery. If I donât eat pretty soonââ

âWeâll take care of that,â his sister promised.

Tony anchored the Napoli in a scallop-shaped cove, and the young people waded ashore, carrying the baskets of food with them.

âThis is an ideal spot for a beach party,â Callie said enthusiastically.

She and Iola took charge and gave orders. Frank and Tony were asked to collect driftwood, while Chet and Joe gathered plenty of seaweed. In a few minutes they returned.

âThose stones over there will make a good place for the fire,â said Callie.

She had found a natural pit among the rocks. In it the boys piled the driftwood, then lighted it. Soon there was a roaring blaze. Frank heaped more rocks into the fire.

When the stones were red-hot and the flames had died out, they placed a layer of seaweed over them. Then the girls laid the lobsters, clams, and corn on the cob in rows and piled on several more layers of seaweed.

âI can hardly wait,â Chet groaned hungrily as he sniffed the tantalizing aroma of the clams.

While the food was steaming, the Hardys brought their friends up to date on Bowden, Latsky, and the search for the demiculverin.

âLater today Joe and I want to climb to the top of Piratesâ Hill and look for the cannon,â Frank told them.

A few minutes later Iola announced that the food was ready. They gathered around as Joe cleared away the hot seaweed.

âRight this way, folks!â he called out. âFirst plateful of juicy sizzling hot clams goes to Miss Iola Morton!â

One by one the picknickers came forward and piled their plates. Every clam, lobster, and ear of corn disappeared. Then a huge watermelon was cut into sections and served.

Forty minutes later Chet rolled over on the sand. âI canât move!â he moaned.

âNeither can I!â Joe echoed. âGirls, that was the greatest meal I ever ate!â

There was little conversation during the next hour. Chet was soon snoring and the others stretched out for a rest. But finally they arose and walked toward the waterâs edge. Chet was the last to join the group.

âHow about my doing that skin diving now?â he suggested.

âOkay,â said Frank, and helped his chubby friend into the equipment.

âIâll follow you,â said Joe, and started putting on his flippers.

Chet lunged forward and stepped into deep water. Almost at once he vanished beneath the surface. Then Joe, too, submerged.

Ten minutes later Chet came up and sloshed to the beach. He removed his face mask and grinned.

âBrought you some souvenirs, girls,â he said, and laid a large handful of unusual shells streaked with mother-of-pearl on the sand,

âOh, theyâre beautiful!â Callie exclaimed.

Iola clapped Chet on the shoulder. âIâm proud of you, brother. Hope thereâs a pearl among these.â

âHow far down did you go?â Tony asked him.

âAbout twenty feet,â Chet stated. âIâll go deeper next time. And hereâs something else I found.â

From one of his belts he brought out what looked like part of a rusty ice pick.

Tony grinned. âI suppose a whale dropped this. He likes his drinks cold and chips off the icebergs with it.â

Chet ignored the gibe. âIâm going to keep it as a souvenir!â

âJoe should have come back by this time,â Frank remarked.

Everyone looked toward the water. There was no sign of his brother. Frank became uneasy.

âIâm going to look for Joe,â he announced.

Putting on his gear, he hurried into the water and soon was lost to sight. Frank swam up and down the coast off Piratesâ Hill but did not see Joe. A sinking feeling came over him. Suppose his brother had been attacked by the ray!

Then a more alarming thought struck Frank. He suddenly recalled the black-garbed skin diver who had speared his air hose earlier that week. Perhaps the man had returned!

Frank struck out faster and peered around anxiously. Suddenly above him he saw a swimmer whose body extended upright. He was clinging to a boat.

âJoe!â he thought, and hurried toward the figure.

His brother was grasping the gunwale of the Napoli, his face mask removed. Frank surfaced alongside of him and took off his own mask.

âHey, Joe!â he cried out. âYou gave us a scare! Where have you been?â

âSorry, pal,â Joe replied. âI was lying in the bottom of the Napoli.â

âWhy?â Frank asked in amazement.

âIâve been spying on a spy,â Joe replied. âLook to the top of Piratesâ Hill! See that figure silhouetted up there? Heâs been watching every move you and the others have been making on the beach!â

âThat guyâs doing more than watching,â said Frank, staring at the lone man on the summit of the hill. âHeâs digging!â

CHAPTER IX

A Surprising Suspect

FROM where the Hardys were clinging to the Napoli, it certainly appeared as if the man were turning up the sand. He held something resembling a blunt shovel in his hands.

âHe didnât have that before,â Joe stated. âMust have just picked it up.â

âMaybe he figured after watching us a while that we werenât about to climb the hill,â Frank deduced. âSo he feels safe to dig for whatever heâs trying to locate.â

âHe might even be burying something,â Joe suggested.

âWell, letâs find out what heâs up to.â

The Hardys donned their masks and swam underwater to shore. Quickly they told their friends about the man on the hill and their desire to see him at close range.

âI suggest that we separate and start looking for driftwood,â Frank said. âThen Joe and I will quietly leave the rest of you and sneak up the hill.â

The others agreed, promising not to alert the man by looking up. Joe pointed out a circuitous route to the top which would escape the notice of anyone above.

âYou take that way, Frank. Iâll wander down the beach and go up from another direction. Weâll try a pincer movement on the fellow.â

âOkay. I wonder if heâs Latsky.â

âMaybe heâs Bowden.â

The picnickers began gathering driftwood, calling out in loud voices which they hoped would carry to the mysterious digger.

Minutes later the Hardys were on their separate ways up the hill. They slipped and slid in the heavy sand. Progress was slow, but finally both reached the crest. Frank and Joe were about three hundred feet apart as they poked their heads above the top and looked around.

The man was nowhere in sight!

Thinking he might be hiding below a hillock of sand, the Hardys walked toward each other, keeping careful watch. They met without seeing the digger.

âWhereâd he go?â Joe asked in disgust. âDo you suppose we scared him off?â

âThere ought to be footprints.â

The boys searched and finally found them. They were large and far apart, indicating that they had been made by a tall man.

âThey go off in the direction of Sergeant Tiltonâs house,â Frank noted. âBut the prints canât be hisâhe isnât that tall.â

The marks might belong to Latsky or Bowden, the Hardys decided. Mystified, they followed the prints. Suddenly Joe grabbed Frankâs arm.

âIf it was Latsky, and if he was the one who stole the cutlasses, maybe he was burying them here until the police alert is over.â

The boys turned back and dug as best they could with their hands around the area where the stranger had been standing. But nothing came to light.

âLetâs go,â Joe suggested. âWeâre giving that man too much of a head start.â

The Hardys hurried along the trail.

Tiltonâs house, a quaint one-story shingled cottage, stood about three hundred feet away. The hill alternately dipped and rose twice to the high point where the structure was located.

âThe footprints lead right to the door!â Frank observed.

Watching to see if anyone might be looking from a window, Frank and Joe walked up and knocked at the door. There was no answer. Frank knocked again. This time someone within stirred. Footsteps sounded and a moment later Sergeant Tilton opened the door.

âWell, this seems to be visitorsâ day around here!â he said, smiling. âWelcome! Come in!â

âDid you have another caller?â Frank asked, pretending it was just a casual question.

âYep.â

Sergeant Tilton explained that only a short while ago a stranger had stopped at the cottage.

âWhere is he now?â Joe asked quickly.

âOn his way back to Bayport,â Tilton replied. âHe was askinâ the best way to go.â

âWho was he?â Joe prodded.

âDonât rightly know,â Tilton answered. âHe never said.â

âWhat did he look like?â Frank asked.

âTall young man. Right nice face. Kind oâ greenish eyes anâ brown hair. Say, why are you two fellows so interested in this guy?â

The Hardys told Tilton it was because of their advertisement for information about cannon which the sergeant had answered.

âSo if any people are going to dig for it on Piratesâ Hill,â Frank added, âJoe and I want to be the ones.â

The man chuckled. âCanât say I blame you.â

Frank now told Sergeant Tilton about Mr. Lightbodyâs account of the Battle of Bayport. âDo you think there could be any connection between that battle and the cannon you think is buried somewhere up here?â

âI sure do,â Tilton replied. âThere were some crooked dealinâs between those old pirates anâ certain folks here in those days. I figger mebbe somebody ashore was trying to sell the cannon or trade it fer the buccaneersâ loot.â

The sergeant suddenly grinned impishly. âIâve got a pirate den. Dâyou want to see it?â

âPirate den!â Joe exclaimed.

âYes sirree!â the elderly man replied. âJust follow me.â

Though the Hardys felt they should hurry off and try to overtake the young man they wanted to interrogate, they were tempted by Tiltonâs invitation. A few minutes would not make much difference. Furthermore, they might pick up some valuable information among his treasures.

âAll right,â said Frank.

Sergeant Tilton led the boys to the kitchen. From an opening in the ceiling hung a rope ladder. The old man grabbed it and thrust his foot into the first rung.

âUp we go!â He laughed. âThis is a real genu-wine freebootersâ cave I got fer myself up here.â

Frank and Joe clambered up after him into the darkness of the room overhead.

âIâll turn on the lantern,â Tilton said. âI made this den out of a storage attic. Thereâs no window. But no self-respectinâ pirate would want a window in his den, anyway.â

He switched on a shipâs lantern in a corner of the room. The first thing the boys noted in its dim glow was a pair of cutlasses. For a moment they wondered if the weapons could be part of the stolen collection. But just then Tilton blew a cloud of dust off them, in order to show them to better advantage. They had definitely been in the den a long time!

âLook at those treasure chests!â Joe cried out. âAnd all those guns!â

The room contained an amazing collection of corsair relics. Coins, rusted implements, old maps, pirate flags and costumes, and faded oil paintings of famous buccaneers decorated the walls and tables. On a rack in one corner hung a variety of old Army uniforms.

âThis is great!â said Joe, and Frank added, âI wish we had time to examine each piece. Iâd like to come again, Sergeant Tilton.â

âYouâre welcome any time,â the man said.

The boys preceded him down the ladder. As they were about to leave, Tilton said, âYou know, I plumb forgot to mention something to you. The young fellow that was here a little while agoâheâs lookinâ for a cannon, too!â

âHe is!â Frank exclaimed. âDid he say what kind?â

âAn old Spanish demiculverin.â

Frank and Joe looked at each other excitedly. They must find the stranger!

âThanks a lot, Sergeant Tilton,â Frank said. âYouâve been a big help.â

âDonât mention it. And hurry back fer a real Visit.â

The Hardys promised and waved good-by. Then, following the large footprints that led away from Tiltonâs cottage, they hurried on. The tracks led down the side of one hill and up another, but Frank and Joe did not spot their quarry.

At last they reached a point as high as the one on which Tiltonâs house was situated. Suddenly Joe stopped and gripped Frankâs arm. He pointed to a figure in a depression between dunes.

âThere he is!â

âDonât let him get out of sight!â Frank urged, running in a westerly direction through the tall grass.

But at that moment the stranger entered the first of a series of deep dips in the sand.

âOh!â Joe cried out suddenly. His right foot had slid into a hole. As he pitched forward, he felt a searing pain in his leg.

Frank turned and came back. Kneeling beside Joe, he felt the injured ankle joint. âYou must have wrenched it. Better not step on your foot. Lean on me.â

âOkay,â said Joe. He was annoyed at himself. âThat ends our little posse.â

âNever mind,â said Frank. âIâll help you back to the beach and weâll attend to your ankle there.â

In their concern over Joeâs injury, both boys had stopped looking for the man. Now they peered across the sand hills, but did not spot him.

Moving as fast as Joeâs ankle would permit, they neared the picnic spot. A fire was blazing. The Hardys grinned when they saw Chet cooking frankfurters.

âOur friend must have a vacuum for a stomach,â Joe remarked.

Frank did not reply. He was gazing intently at a strange young man who was watching Chet and chatting pleasantly with the girls. The fellow, about twenty-eight years old, was very tall, and had a determined, jutting jaw.

âJoe,â Frank said excitedly, âunless my eyes deceive me, the man we were chasing has walked right into our camp!â

âOne thing is for sure,â Joe said. âHeâs not trying to avoid us now.â

âWeâre not sure he was doing it before,â Frank said thoughtfully. âOn the other hand, maybe he changed his strategy. He might still want to find out whether we came here to look for a cannon besides having a picnic.â

âWeâd better be cagey,â Joe said.

As the Hardys drew closer, Iola handed the stranger a frankfurter on a roll. A moment later she looked up and saw them.

âWhy, Joe, what happened to your foot?â she cried out and ran toward him.

âI twisted it,â Joe explained.

âIâm sorry you hurt yourself,â Iola went on and added, âWeâve got company. This is Tim GermanâFrank and Joe Hardy.â

The boys shook hands with Gorman. The same thought went through their minds after they had a close look at him. He was the man who had passed them in a car two days before and had stared so intently at them!

The stranger seemed to sense what they were thinking and mentioned the incident before they had a chance.

âI was looking for someone I know who has the same kind of car as yours,â he explained.

Frank and Joe nodded. At the same moment Callie remarked, âTim Gorman tells us that he has just been to see Mr. Tilton.â

âYes,â the visitor said. âI had a very interesting talk with the old sergeant.â

âWe know,â Frank told him. âWe were up there too.â

âAnd I just about broke my leg trying to catch up with you on the hill!â Joe declared. âYou certainly crossed it in a hurry.â

âReally? Why didnât you call?â Gorman replied. âI didnât see you.â

The Hardysâ suspicious attitude softened considerably. Gorman now offered to work on Joeâs ankle. He made an ice pack with a towel and cubes from the picnic basket, and applied it to the swelling. Next, he massaged the joint carefully. In a few minutes Joe said it felt much better.

âThanks,â he said as the man rose.

Frank steered the conversation back to Sergeant Tilton. Gorman talked freely, laughing about the amazing pirate den in the attic and the talkative old manâs preposterous stories. But he did not mention the cannon, nor give an inkling of why he had been on Piratesâ Hill.

Finally Joe could wait no longer to broach the subject. Bluntly he said, âWe understand youâre looking for a cannon.â

Gormanâs face clouded. âI suppose Tilton told you that,â he said, his jaw set and his eyes flashing. âThat man talks too much. I asked him to keep the information to himself and he told me he would.â

âIs it a secret?â Chet asked.

Their visitor looked annoyed, but he regained his composure quickly. âI suppose you might say so,â he replied, looking off into space as if trying to decide whether or not to reveal it.

âJoe, what happened to your fool?â
Iola cried out

A sudden quiet descended upon the group. The Hardysâ friends waited for the brothers to carry on the conversation.

Tim Gorman relaxed a little, and said, âI may as well admit that Iâm looking for a cannon.â He paused. âBut Iâd rather not say anything more about it.â

âAs you wish,â Frank said politely. âBut we might be able to help you. Joe and I have been reading about cannons.â

Gorman smiled and said, âI feel itâs best that I keep my business to myself. Perhaps later on I could discuss the situation with you.â

The pleasant way in which he made the latter statement and the smile which went with it tended to disarm all of the group except Frank and Joe. Though Gorman was friendly, they still felt he was somewhat suspect. Not once had he mentioned a demiculverin, though that was, according to Tilton, what he hoped to find.

âWeâll probably see one another,â Gorman announced. âIâm staying in Bayport.â

Tony Prito asked Gorman if he would like to go back to town with them in the Napoli.

âThanks very much,â Gorman answered. âBut my car is parked over on the shore road.â

He started to say good-by, then suddenly he stopped short and stared at an object in Iolaâs hand. It was the ice pick Chet had found. She was about to put it in the picnic basket.

Gorman stepped forward. âWhere did you get that?â he asked intently.

Chet proudly informed him of his underwater discovery as Iola handed over the pick. The man examined it closely.

âIs it an antique ice pick?â Chet asked him.

Gorman swung about, his face flushed with excitement. âThis is not an ice pick. Itâs a gunnerâs pick! There was a cannon near here!â

CHAPTER X

Fireworks!

TIM Gormanâs announcement sent a thrill of excitement through the Hardy boys. There was no question now that a cannon had been on Piratesâ Hill. But was it still buried deep under the sand?

Frank was the first to speak. âHave you any idea, Tim, what kind of cannon it might have been?â

âThereâs absolutely no way of telling,â Gorman replied slowly.

Chet had walked up to face their visitor. âHow did you know this gadget was really a gunnerâs pick?â he asked.

âLike Frank and Joe, Iâve been reading a good deal about artillery,â the young man replied. He turned the pick over in his hands and continued, âThis is part of a gunnerâs equipment.â

âHow was the pick used?â Chet inquired.

Gorman explained that by the eighteenth century, powder bags had come into wide use, replacing the loose powder which had formerly been ladled into the bore of a cannon.

âThis made it necessary to prick open the bag inside the cannon so the priming fire from the vent could reach the charge. This tool did the trick.â

Gorman smiled. âIâll be glad to give you cannon instruction any time, but I must be off now.â

He shook hands with everyone and said good-by. When he was out of sight, Callie said:

âYouâd better dig for that cannon pretty soon or Gorman will find it first.â

âLetâs start right now,â Frank urged.

Acting as leader he assigned the others to various spots and for an hour the beach and hillside were beehives of activity. Various small objects were dug up but there was no sign of a cannon.

âI guess weâll have to quit!â Tony called out to Frank. He explained that he had promised to be home for supper by seven and take his parents in the Napoli later to see the fireworks.

âWeâre all going in the Sleuth,â said Iola. âSorry you canât join us, Tony.â

The tools were collected and carried out to the boat along with the picnic baskets. After everyone was seated, Tony headed back toward town. Frank and Joe sat alone in the prow for a while discussing Gorman. Frank said he was convinced the young man was aboveboard, but Joe was still suspicious.

âHe may just be a very smooth operator,â Joe remarked. âWhy, he might even be in league with Latsky!â

The boysâ discussion was interrupted by a call from Callie. âOh, look, everybody!â

The Napoli had turned into the bay and was running close to shore where an area of the water had been roped off for the eveningâs display of fireworks. A small grandstand had been erected along the bank. In the water two large scows contained the set pieces and the rockets which would be sent skyward during the celebration.

âLooks as if itâll be a good show,â Tony remarked.

Chet proposed that they come early in the Sleuth and anchor as close as possible to the two barges so they could get an excellent view of the performance.

At eight-thirty Frank and Joe went to their boathouse where Chet and the girls were waiting. Soon the group was aboard the Sleuth, heading out to the area where the fireworks were to be displayed. Nearing it, they could hear band music from the grandstand on the shore.

A large crowd was gathered both on the bank and on the water. Small craft filled with onlookers bustled in the harbor, each skipper seeking a good place from which to view the fireworks.

Frank guided the Sleuth close to the roped-off area. Floodlights set up on the scows made the scene as bright as day.

As Frank turned off the motor, Joe, seated alongside him, suddenly grabbed his arm.

âWhatâs up?â Frank asked, turning. He noticed a worried look on his brotherâs face.

âThe man who seems to be in charge of the fireworks display is the one who warned us about the sting ray!â

Frank gazed ahead and nodded. âI wonder if the fellow who was hiding in the bottom of his boat is here too.â

There was no possible way to find out now. It was two minutes to nine. The man was hastily directing several workers, none of whom was familiar to the boys.

âTheyâre going to start!â Chet called.

A moment later there was a swish and whine as the first rocket was set off. It shot high into the dark sky above the harbor and a fountain of cascading diamonds burst into life. Ohs and ahs echoed from the onlookers.

A second and a third rocket swirled heavenward. Red and blue sparkles gleamed brilliantly after the sharp explosions.

âThis is wonderful!â Iola cried out.

âOh, theyâre going to set off one of the figures!â Callie said excitedly. âLook, itâs a man pedaling a bicycle!â

A twenty-foot figure, sputtering yellow-white smoke, appeared to be cycling across the barge.

âThere goes another figure!â Chet cried in delight as a multicolored clown began to dance with slow, jerky motions.

Just then a hissing sound attracted the attention of the Hardys and their friends. The next moment a shriek went up from the girls.

A rocket had been fired horizontally and was streaking directly toward them!

Terrified, everyone in the Sleuth sprawled flat, as it skittered over the waves like a guided missile!

Whack! A shudder went through the boat as the rocket glanced off her bow. A thundering blast followed when it exploded ten yards off the starboard side.

Streamers of white light ribboned across the motorboat, but the hot rocket itself sizzled on the surface of the water and then died out in a cloud of acrid smoke.

âThat was too close for comfort!â Joe cried out, jumping up.

Frank leaped back to the wheel as Chet, Iola, and Callie sat up and peered over the gunwales toward the barge.

âThat was no accident!â Frank stormed. âIâm going after the man who set off the rocket!â

âPour it on!â Joe shouted.

The motor roared to life and the propeller kicked up white foam as the Sleuth shot ahead and ducked under the rope of the danger zone.

Closing in rapidly on the barge, the Hardys noticed that one of the Bayport Police Department launches was approaching from the opposite side. Its two powerful spotlights were raking the fireworks platform and the officers were shouting that there was to be no more firing.

âLook!â Joe cried. âThat guy over there isnât paying any attention!â

A stranger to the Hardys, he grabbed a lighted torch from the hands of the head man and started for one of the rockets.

âHeâll blow us all up!â Callie cried in terror.

A second later the young people saw him run from fixture to fixture, touching his torch to the fuses of the entire remaining display.

Frank did not wait. He put the Sleuth in reverse, and the motorboat skittered backward.

The next moment the bay shook with the din of the bursting pyrotechnics. Rockets spewed in all directions with thunderous detonations.

The danger of being struck by the flying missiles also drove the police launch back from the barge toward the center of the bay. There were anxious moments as the bombardment continued.

Hot fragments from the bursting rockets sprayed the deck and cockpit of the Sleuth, but finally Frank got beyond their range.

The din aboard the barge ended as abruptly as it had begun.

âWhat a crazy, stupid thing to do!â Joe exclaimed,

âIâd like to punch the guy who set off those rockets,â Frank declared.

âYouâll have a hard time,â Chet said. âAll the men on the barges jumped overboard and are swimming to shore.â

Frank turned the boat and headed for the beach. The stranger who had caused the uproar was not in sight, but the man who had warned them of the sting ray was still in the water. Frank drew alongside of him and throttled the engine.

âClimb in!â he called.

The man pulled himself aboard. At the same time the police launch picked up several other swimmers. Not one of them was the fellow the Hardys wanted to interrogate. But they began to question their new passenger.

âWho was the guy who started that explosion?â Joe demanded.

âI donât know.â

âWhat do you mean? You were supervising the fireworks, werenât you, Mr.â?â

The man scowled. âThe nameâs Halpen. I was only in charge of the timing,â he answered. âThe fellows lighted the fuses when I told âem to. I donât know the name of the guy who disobeyed orders. He just came around before we were ready to start. I suppose somebody hired him. It wasnât any of my business.â

Frank was not satisfied with the explanation. He hailed the captain of the police boat and asked if he might speak to the men they had picked up.

âSure thing, Frank,â said the officer.

The captain requested the men to come to the near side of his craft. Frank asked them the name of the worker who had set off the rockets. Each declared he did not know.

Their own passenger grunted. âI guess the guy just butted in for a good time.â He eyed the Hardys. âUnless,â he went on, âhe was an enemy of yours.â

âIf he was, we didnât know it,â Joe retorted quickly. âBut he sure is now!â

âIâm getting cold,â said Halpen. âPut me ashore, will you?â

âOkay, but first 1 want to ask you a few questions,â Joe spoke up.

âWell, make it snappy!â

âWho was the man hidden under the tarpaulin in your boat this morning!â Joe shot at him.

Halpenâs jaw sagged, his composure gone for a moment. Then he said, âYou saw him, eh? Well, he was a stranger to me. His boat capsized and I picked him up. He didnât tell me his name.â

âBut why did he hide under the cover?â

âAfraid of the sun,â Halpen answered gruffly. âAnd he fell asleep.â

Frank took up the questioning. âWhy did you race off in your speedboat when we tried to overtake you?â

Halpen glared at him. âIt was late. My wife was waiting for me. And now, unless youâre going ashore, let me get into the police boat so I can go home.â

The Hardys were frustrated, but there was nothing they could do. Frank helped the man board the launch, and it took off for Bayport immediately.

Iola grimaced. âI donât believe a word that man said, do you?â

There was a chorus of âNoâs.â Joe said he was going to find out who Halpen was and what he did for a living.

âProbably nothing much,â Chet spoke up, opening one of the picnic baskets. âWho wants a sandwich and a soda?â

Everyone did and in a short while all the food was gone. Chet declared that he was still hungry, and upon reaching the Hardysâ boathouse, the group set off for a spot frequented by teen-agers.

Immediately the Hardys and their friends went to phone their families that they were all right. Then Joe called the chairman of the fireworks committee, Mr. Atkin. He had just reached home.

âHalpenâs harmless but a loafer,â Mr. Atkin said in answer to Joeâs question. âHe manages to get along somehow, doing odd jobs. At one time he worked in a pyrotechnics factory and understands fireworks. Heâs had the job of setting off the Bayport rockets and set pieces for the last few years. I canât understand what happened tonight.â

Joe now inquired how many men had been engaged to work on the fireworks display.

âLetâs see,â said Mr. Atkin. âFive. Yes, there were five.â

âI counted six,â Joe stated. âWhat?â the man exclaimed. âThen one of them was there without being hired. He probably was the one who caused a near tragedy.â

âIâm sure the mysterious Mr. X was the culprit,â Joe agreed. Upon returning to the group, he told the others that so far Halpenâs story checked. âItâs a puzzle, though. I have a hunch heâs not to be trusted.â

Frank remarked that he was more worried about the mysterious man who aimed the rocket at them.

The thought of their close escape sobered the group. It was not until some of their high school friends stopped at the table and began to joke with them that they shook off the depressed mood, and enjoyed the remainder of the evening.

The next morning, while the boys were dressing, Frank said he thought they should get in touch with Bowden before making a further search. âSince both he and Tim Gorman are looking for the demiculverin, Iâd like to know if theyâre acquainted.â

âLetâs go!â

âWeâll tell him Chet found a gunnerâs pick along the shore, but we wonât mention Piratesâ Hill.â

âRight.â

The man seemed a bit less friendly than usual when they arrived at his motel. Was he suspicious? But when the boys finished telling their story, he smiled. âYouâre making progress, I can see that. Keep it up. Time is precious.â

Bowden had nothing to offer in the way of news. The police, he said, had no clues to the person who had left him the warning note and later attacked him.

Presently Frank asked, âDo you know a man named Tim Gorman?â

Bowden was visibly disturbed by the question. âGorman!â he exclaimed, his face flushing. âIâll say I know him, but Iâm not proud of it.â

âWhat do you mean?â Joe asked.

âHeâs no good!â Bowden told the boys that Gorman went about posing as a naval man and was wanted by the police for swindling.

âThatâs hard to believe,â Frank said.

Joe, on the other hand, arched his eyebrows and gave his brother a meaningful look as if to say, âI told you so.â

Bowden asked them how they happened to know Gorman. Guardedly Frank told of meeting him on the beach. Bowden interrupted the narration several times to inquire about details. There seemed to be something he wanted to know, but was reluctant to ask point-blank.

Finally, unable to suppress his curiosity any longer, he blurted out, âDid Gorman mention the cutlass?â

CHAPTER XI

An Alias

BOWDENâS unexpected question perplexed the boys for an instant. Then Joe asked, âOne of the stolen cutlasses?â

Bowden looked blank. âWhat stolen cutlasses?â âYou donât seem to read the newspaper,â Frank said. âSome swords were stolen from the Bayport Historical Society building the night before last.â

Bowdenâs surprise seemed genuine and the Hardys concluded that he had nothing to do with the theft.

âWell, what cutlass were you talking about?â Joe asked.

âForget it.â

âLook, Mr. Bowden, you canât play hide-and-seek with facts and expect us to do a good sleuthing job for you!â

The man smiled. âNo need for you to get hot under the collar. Gormanâs hipped on finding a miniature cutlassâsays itâs a lost heirloom. He puts the question to everyone.â

The Hardys thought this was an unlikely story. They left shortly, saying they planned to continue their search for the cannon.

âI wish Dad would come back from Florida,â Joe remarked as they rode along. âThis case is getting knotty.â

âJoe, it had me baffled until just now. But I believe I have the answer,â Frank declared.

âWhat is it?â

âIt might sound farfetched,â Frank replied, âbut the combination of cannons, cutlasses, and the story about the piratesâ fight all lead in one direction.â

Joe smiled. âYou mean hidden treasure?â

âRight. But weâll have to dig up more clues before we can dig up any treasure,â Frank said.

Since the boys had to pass near their home to take the road to Piratesâ Hill, Frank suggested that they stop and see if there was a letter or phone message from Mr. Hardy.

The telephone was ringing persistently as they entered the house. âNobodyâs home,â Frank said. âGrab it, Joe.â

The boy picked up the instrument in the front hall. âYes, this is Joe Hardy.... Why do you want to see us, Mr. Smedick?â Joe listened for a moment and added, âAll right. Frank and I will come immediately.â

Joe hung up and turned to his brother. âA guy with a strained voice, named A. B. Smedick, wants to see us at the Bayport Hotel. Room 309. It has something to do with the cannon mystery.â

âWeâd better watch out. This may be a trap. I suggest we stay in the hall to talk to that fellow,â Frank cautioned.

A few minutes later Joe buzzed 309. Presently the door opened. The Hardys gasped. Tim Gorman stood there!

âWhatâs the idea of this?â Joe asked.

âPlease step in,â Gorman invited. âIâll explain.â

âWe prefer staying here,â Frank said coolly.

Quickly Gorman reached into his coat pocket, extracted a wallet, and took out a paper and a card. He handed them to Frank.

On the card the boys saw the small photograph of the man in a Navy uniform. Joe inspected it closely to see if any touching up had been done.

It was Gorman, all right, beyond any doubt. The paper was a statement of his honorable discharge from the United States Navy two years earlier.

âPlease come in,â Gorman said, and the Hardys entered the room. Their host locked the door and they all sat down close together.

âIâm using the name of Smedick here for protection against certain people in Bayport who would like to see me harmed,â he said in a low voice. Obviously he was afraid that he might be overheard.

Without explaining further, he went on, âIâve investigated you boys thoroughly and know youâre trustworthy. Iâm very eager to have you help me solve a mystery.â

âWeâre pretty busy right now on another case,â said Joe, who still felt skeptical about the man.

Gorman looked disappointed. âIâm sorry to hear that. I really need your help.â

Frank suggested that Gorman tell them what the mystery was. Perhaps they could work on it along with their other sleuthing.

Gorman pulled a pad and pencil from his pocket and wrote:

MEET ME TOMORROW AT 2 P.M. IN THE BROWN SHACK ON THE DUNE A MILE NORTH OF PIRATESâ HILL. IâLL TELL YOU THEN.

The boys read the message. Frank nodded. But Joe, suspicious, said, âBefore we go any further, suppose you tell us what you know about cutlasses.â

The boyâs remark hit Gorman like a bombshell. He sat bolt upright in his chair, and his face flushed. âPlease, not now,â he said in a strained voice. âTomorrow. Iâll tell you then.â

He arose, took a lighter from his pocket, and burned the note. Then he walked to the door, unlocked it, and ushered the boys out.

The Hardys did not speak until they reached their car. Then, as they drove off, Joe burst out, âWhat do you make of all this?â

Frank said his curiosity was aroused and he would like to go to the shack. âBut Iâll watch out for any double-crossing.â

âWell, weâd better get back to our search for the demiculverin,â Joe urged.

âLetâs borrow Dadâs magnetometer,â Frank added. This was an electronic mine detector for locating metals under sand.

They picked up the instrument at their house, then drove to Piratesâ Hill.

âLetâs do our searching systematically,â Frank said. He proposed that they mark off sectors and work along the beach and the dunes, moving slowly up the hill.

They worked steadily until one oâclock. The magnetometer had indicated nothing of importance. The boys sat down to rest and eat the sandwiches they had brought. It was ebb tide and the beach was deserted.

As soon as they had finished, they resumed their work with the magnetometer. Whenever it indicated a metal object under the sand, the boys dug hopefully. As time passed, they discovered a battered watch, a charm bracelet and a cheap ring, along with soda cans and an old, rusty anchor.

âSay, we could open a secondhand store,â Joe quipped.

âA junk yardâs more like it,â Frank said.

By five oâclock they had dug several holes on the beach and part of the hill but had not found any artillery. Unfortunately, the magnetometer short-circuited. It would take some time to repair it, they knew. Weary, they gave up the search.

âAt this rate itâll take us all summer to cover Piratesâ Hill,â Frank remarked, flopping down on the sand.

âYes, and Bowdenâs in a hurry,â Joe answered with a grin.

They went back to their convertible and started homeward. Soon after dinner the phone rang. It was Chief Collig.

âI have some important news for you,â he told Frank, who had answered.

âWhatâs up, Chief?â

âFirst, I want to tell you that we still have the stakeout posted at the cabin in the woods, but no one has showed up yet.â

âToo bad,â said Frank.

âSecond, the department has been working on the fireworks case. Since you fellows are interested in finding that phony helper I thought youâd like to know weâve traced him to a rooming house.â

âWhere?â Frank asked.

âRight here in Bayport. His name is Guinness. He skipped out just before we got there, but we picked up a clue that may help us locate him. Officer Smuff discovered it in a wastebasket in Guinnessâs room.â

Frank gripped the phone excitedly. âWhat is it?â

âAn address on a scrap of paper,â the chief replied. âIt reads A. B. Smedick, B. H.â

CHAPTER XII

Startling Developments

STUNNED by the information, Frank echoed, âA. B. Smedick, B. H.!â

âRight,â said the police chief. âWhat do you think B. H. stands for?â

âIâm sure that it means Bayport Hotel,â Frank replied, âbecause we talked to a person there by that name.â

âWhat! Well, then, maybe you can tell us where Smedick is now. He checked out.â

Frank, amazed to hear this, said he had no idea. âJoe and I are supposed to meet him tomorrow afternoon along the shore. He probably wonât show up. But if he does, Iâll try to find out if he knows where Guinness is.â

âDo that,â said Chief Collig and hung up.

As soon as Frank replaced the phone in its cradle, he rushed to tell Joe, his mother, and Aunt Gertrude the news.

âIt sounds to me,â Aunt Gertrude commented, her jaw set firmly, âas if everybody connected with this Piratesâ Hill mystery is a criminal.â

âYou could be right. At this point Iâm beginning to think Joeâs suspicions about Gorman might be justified,â Frank remarked.

Joe gave a knowing grin. âI thought youâd agree sooner or later.â

âHold on! I didnât say Iâm entirely convinced. Iâll let you know after we talk to him at that shack tomorrow afternoon.â

âIf he shows up,â Joe added.

Next morning, when the boys awoke, a heavy rain was falling. Jumping out of bed to close the window, Frank remarked, âIt doesnât look as if weâll be able to do any searching at Piratesâ Hill today.â

After breakfast they decided to spend the morning doing some sleuthing on the stolen cutlasses.

âThereâs a good chance that they may have turned up at some of the antique shops and pawnbrokers by this time,â Frank observed.

The boysâ first stop was a curio shop near the Bayport railroad station. The visit there was fruitless.

Next the Hardys drove across town to a shabby antique shop, owned and operated by Robert Dumian.

âI had some cutlasses,â the dealer replied to Frankâs question. He eyed the boys with curiosity over his bifocal glasses. âItâs funny youâre wanting them. Yesterday a boy named Gil Fanningâabout eighteen years oldâbrought five cutlasses in here to sell. Told me they were family relics.â

âIs he a local boy?â Frank asked, interested at once.

âYes, he lives in Bayport,â Mr. Dumian answered. âOn Central Avenue. I paid him twenty dollars apieceâa pretty steep price, but they were the real thing. Five beautiful swords!â

âMay we see them?â Frank asked eagerly. The thought that they might be the Entwistle relics caused his heart to beat faster.

âIâm sorry,â the dealer replied. âRight after Fanning brought the weapons in, a swarthy-looking fellow in a black motorcycle jacket came into the shop and bought every one! He didnât give me his name.â

The Hardys shot chagrined looks at each other. It appeared that Latsky had beat them to the draw! They were dumbfounded by the appearance of Latsky at the shopâassuming that the man in the leather jacket was he. It certainly looked now as if Latsky were not the person who had stolen the cutlasses from the Historical Societyâs building. Could Gil Fanning have been the thief?

âThatâs not all,â the man continued. âLast evening, just as I was closing up shop, a stout boy came in here looking for cutlasses. And now you fellows come in asking for the same thing. I am beginning to wonder if thereââ

âDid the stout boy give his name?â Joe broke in.

âYes,â Mr. Dumian said, turning to a spindle of notes on his desk. âHe wanted me to get in touch with him if any more cutlasses came in. Here it is.â He tore a slip of paper off the spindle and handed it to Frank.

The paper bore the name Chet Morton!

âChet Morton! We know him,â Joe burst out. âWhat would he want with the swords?â

âSearch me,â said Mr. Dumian.

The boys thanked him and left the shop. They decided to talk to Gil Fanning, then ride out to Chetâs house and ask him why he was looking for cutlasses.

âWhat a muddle!â Frank exclaimed as they went into a drugstore to look up the name Fanning in the Bayport telephone directory. They found one listed at 70 Central Avenue.

Frank and Joe drove there in the downpour and learned that Gil, an orphan, lived with his grandmother. Tearfully the elderly woman said the boy had not been home for a week.

âHeâs always been hard to manage,â she said, âbut I knew where he was. This is the first time heâs ever stayed away without letting me know where he is.â

âHave you notified the police?â Frank asked.

âOh, no,â Mrs. Fanning replied. âGil phoned heâd be back in a while. Said he had a job and I was not to worry.â Suddenly she asked, âBut why are you here? Is my boy in some kind of trouble?â

âNot that we know of,â Frank answered. âMrs Fanning, did you give Gil permission to sell any of your heirlooms?â

âCutlasses,â Joe added.

A frightened look came over the womanâs face. âYou mean swords? We never had any swords. You must be mistaken.â

âNo doubt.â Frank smiled, not wishing to disturb the elderly woman any further. âWell, thank you,â he said. âI hope Gil returns soon.â

Frank and Joe left, puzzled by the information. After having lunch at a coffee shop, they headed for Chet Mortonâs.

As they neared the farm, the rain ended. They learned from Iola that Chet had taken his flippers and snorkel, and gone to their swimming pool to practice skin diving.

âEver since he found that gunnerâs pick, heâs had a great desire to dive for treasure,â Iola added, smiling.

Frank and Joe told her about their search at Piratesâ Hill the previous day, then went to the pool to talk to Chet about his visit to the antique store.

To their surprise, he was not in sight. At the edge of the pool lay his snorkel and flippers.

The Hardys returned to the farmhouse and told Mrs. Morton and Iola that Chet was not around. Both looked concerned. Mrs. Morton said that he never left without saying where he was going.

âPerhaps he went off with that boy who was here,â Iola suggested. She told the Hardys that about half an hour ago a youth about Chetâs age had strolled in and asked for him. They had directed him to the pool.

âWho was he?â Frank asked.

âWeâd never seen him before,â Iola answered. âHe said his name was Gil. He didnât give his last name.â

Upon hearing this, Frank and Joe told her and Mrs. Morton the whole story of Gil Fanning and the cutlasses.

âIf the boys went off together walking, they probably havenât gone far,â said Frank. âWeâll look for Chet.â

The Hardys hurried off. As they rode along, their eyes constantly swept the landscape, hoping to catch sight of their pal. They went for three miles without passing a car or seeing anyone walking along the road. Presently they came to a combination country store and gasoline station.

âIâll go in and phone Mrs. Morton. Maybe heâs turned up meanwhile,â said Frank, getting out of the car.

Joe followed, hoping that Chet had returned. But when Frank spoke to Mrs. Morton they learned that their pal had not come back and the family had no word from him. Mrs. Morton declared that she was going to call Chief Collig at once.

Leaving the store, Frank turned to Joe. âWhat do you think we should do? Keep hunting for Chet, or go on to the shack?â

âLetâs go on,â Joe replied. âThe police will do everything possible to find Chet.â

As they approached their convertible, Joe gasped and grabbed Frankâs arm.

âOh, no!â he cried out, pointing to the rear tires. Both were flat!

The boys rushed over to the car. Not only were the tires flat, but to their dismay there were huge slashes in them!

âSomeone deliberately cut our tires!â Frank exclaimed.

They wondered whether it had been the malicious mischief of some prankster, or whether one of their enemies was pursuing them and had done it to keep them from meeting Gorman.

âWe have only one spare,â Joe remarked with a groan. âWhere can we get a second?â

âMaybe the storekeeper sells tires,â suggested Frank, and returned to the shop.

Fortunately the man kept a few recaps in his cellar. Frank found one that fit the car and brought it upstairs. Working together, the Hardys soon replaced the slashed tires.

âItâs way after two oâclock,â Frank remarked as they went to wash their hands. âI wonder if Gorman will wait.â

Joe reminded him that the man might not be at the shack at all. He still mistrusted Gorman and was sure a trap had been laid for them.

âMaybe,â said Frank. âAnyway, weâll approach with caution.â

Three miles farther on they reached a side road which they figured would take them near the shack. Presently the road ended and Frank braked the convertible to a stop. Ahead was nothing but sand. The boys got out and looked around.

âThereâs the shack!â Frank pointed to their right as he put the car keys in his pocket.

The ramshackle old building, badly weathered and sagging, stood between two dunes. They trudged toward it through the wet sand, a fine spray from the windswept sea stinging their faces.

âWhat a dismal place!â Frank exclaimed

Joe nodded, âPerfect spot for a trap. I donât believe Gorman came, Frank.â

As they drew closer, they noticed that the front door was wide open. They concluded no one could be inside, for certainly any occupant would have shut the door against the strong winds.

Nevertheless, Frank called out, âTim! Hey, Tim!â

No answer!

âItâs obvious heâs not here,â said Joe. âAnd if this is a trap, weâre not walking into it. Letâs go!â

At that moment the boys heard a muffled cry from inside the shack. Throwing caution aside, they rushed into the building.

The next instant they were seized by two masked men!

CHAPTER XIII

Mixed Identities

AMBUSHED, Frank and Joe fought like wildcats. Their assailants were much heavier in build and held onto the boys with grips of steel. Neither man relaxed his viselike hold for a moment, despite a hard, occasional punch which the Hardys managed to land.

As the boys fought desperately, the face masks slipped off their attackers. The men were strangers to the Hardys.

Joe wrested his right arm free and sent a vicious punch to his adversaryâs jaw. The manâs grip relaxed and he fell back, groggy. This was Joeâs chance for escape!

âHere I come, Frank!â he yelled.

But a kick from the other man sent Joe sprawling. In a flash his own antagonist was on top of him. There was little fight left in his assailant but he depended on his great weight to hold the boy down. Joe could hardly breathe.

At this point Frank was giving his opponent a rough time. The man was now gasping for breath. âIâll let him get really winded,â Frank thought, wriggling even harder to break loose.

âHold still or Iâll finish you for good!â the man threatened.

âJust try it,â Frank grunted defiantly.

He gave another violent twist and almost broke free. But the man retained his powerful hold. An unexpected downward swipe with his stiffened hand caught Frank on the back of the neck and he slumped to the floor.

The man now turned his attention to Joe and helped his accomplice pin him to the floor. They bound and gagged the young detectives, then held a whispered consultation. One of them went into a back room and returned a moment later dragging something in a burlap sack. He slid it into a corner and both men left the shack by the front door.

Frank and Joe heard a muffled groan. A human being was in the sack!

The boys concluded it must be Gorman. He, too, had been ambushed! Were the attackers enemies of Gorman working on their own, or were they in league with Bowden? Or perhaps Latsky?

Desperately the Hardys tried to loosen their bonds. Frank found that by wriggling his jaw and rubbing the gag against his shoulder he could loosen it. At once he cried out:

âGorman!â

As the bundle in the corner moved slightly in reply, they were horrified to see their assailants rush back into the shack. They had heard Frankâs outcry. Without a momentâs hesitation, they knocked both boys unconscious.

Some time later Joe revived. He was amazed to find that he was outdoors and dusk was coming on. He saw Frank not far away and on the other side of him the captive in the burlap sack.

âWeâre in a gully,â Joe thought as he struggled to rise.

His arms were still tied behind him and the gag was in his mouth. Every part of his body ached. He was lying face up in a puddle of rain water and was soaked.

Frank, still unconscious, was also bound and gagged. His position was precarious; he lay in a deeper part of the ditch with water rushing only inches from his nose and mouth. The stream, swollen by the heavy rain, was tumbling along in torrents.

âFrank will drown!â Joe thought in horror. âI must get him out of here!â He struggled desperately and finally by twisting and turning slipped his gag off. But his bonds held firmly.

âFrank!â he shouted. âSit up! Sit up! Youâll drown!â

At first there was no response, then Frank made a feeble effort to rise. He raised his head a few inches and tried to pull himself up, but he lacked the strength. Exhausted, he slumped back into an even more dangerous position.

âI must rescue him!â Joe said to himself.

He dragged his body through the mud to Frank. Rolling onto his side, he was able to clutch his brother by one leg with his tied hands. Getting a firm hold, he pulled Frank inch by inch from the threatening stream.

It was an agonizing task. The sharp gravel on the edges of the gully scraped Joeâs cheeks, but finally he brought Frank to a safe spot. He managed to remove the gag, but the knots on Frankâs bonds defied him.

âWeâd better give this up,â said Joe, âor I may be too late to save Gorman.â

âGo ahead,â Frank said weakly. His own arms had no feeling in them.

The burlap sack lay only slightly out of water. âThose thugs must have figured on having the three of us drown in the stream. They evidently sent us rolling down the bank, but we didnât go far enough,â Joe thought.

Redoubling his efforts, he crawled to the burlap sack and attempted to secure a hold similar to the one on his brother. But the embankment here had a slimy mud surface. With each attempt to haul the sack away from the water, Joe lost ground.

âIâll never get Gorman out this way!â he groaned. âIâll have to get my hands free.â

His bonds were as tight as ever. Joe decided to crawl back to Frank and have him work on the knots again. Halfway to his goal, he heard the sound of an approaching car. Apparently there was a road above the gully!

âHelp! Help!â Joe cried out.

The car went by and the boyâs heart sank. He yelled even louder. To his immense relief, he heard the car slow down. Then it stopped.

A door slammed, and Joe continued his cries for help. Someone came running and leaned over the rim of the gully.

Bowden!

âJoe Hardy!â the man cried out. âWhat happened to you?â

âCome down here, quick!â Joe yelled, âUntie me! And we must get the others out!â

Bowden, his raincoat flapping in the wind, grabbed the overhanging branch of a nearby tree for support and slid down the embankment.

âThereâs a penknife in my pocket,â Joe told him. âGet it out and cut me loose.â

Bowden did so, and together he and Joe freed Frank and assisted him to his feet.

Joe pulled Frank from the threatening stream

The burlap sack began to move. Bowden jumped back, startled. âFor Peteâs sake, whatâs in there?â

âItâsââ Joe started to say, when Frank gave him a warning look.

âWe donât know,â Frank spoke up, âbut we figure itâs probably a man. Two thugs knocked Joe and me out. They must have put all three of us in the gully.â

The boys made their way to the sack. Both were thinking the same thing. What was Bowdenâs reaction going to be when he and Gorman faced each other?

With the penknife Joe slashed the cords that bound the burlap sack and yanked it open. A cry of astonishment burst from the Hardys. The prisoner was not Gorman! He was Chet Morton!

The stout boy, bound and gagged, and wearing only swim trunks, gazed at his rescuers dazedly. It was evident he was weak and in a state of shock.

âChet!â the Hardys exclaimed, removing his bonds.

As their pal took in great drafts of fresh air, Bowden asked, âIs he a friend of yours?â

âYes,â Joe replied. âWe must get him home at once.â

âIâll take you there,â Bowden offered.

âThanks. Where are we, anyway?â Frank asked him, slapping and swinging his arms to restore the circulation.

âOn the shore road about ten miles from Bayport. Say, where did you fellows get slugged?â

âSomewhere up on the dunes,â Frank replied offhandedly. He felt in his pocket. The car keys were gone!

Bowden preceded the boys up the steep embankment. Frank and Joe assisted Chet, who could hardly put one foot in front of the other.

âYouâll feel better, pal, as soon as we get you something to eat,â Joe told him.

Chet gave a half-smile and nodded. âAwful hungry,â he admitted.

Out of earshot of Bowden, Frank whispered to Chet, âWe thought you were Gorman.â

âYes,â said Joe. âThat guy double-crossed us.â He looked at Frank. âI guess youâre ready to admit now that Gorman is a phony!â

CHAPTER XIV

Chetâs Kidnap Story

As the three boys followed Bowden to his car, the manâs denunciation of Tim Gorman came back to them. Bowden probably was right, but where did he himself fit into the picture? The Hardys wondered if there were any significance to the fact that he happened to be passing the gully.

âThe less we say the better,â Frank warned the others.

Reaching the car, Joe got into the front seat, ready to grab the controls should Bowden attempt to turn off the main road and lead them into any more trouble. But the man drove along normally and in silence.

Suddenly Joe cried out, âThereâs our car parked just ahead!â It had been pulled way over to the side.

Bowden stopped and waited as the Hardys examined the automobile. The keys were in it and nothing had been disturbed. The motor started at once.

âThanks again, Mr. Bowden,â Frank called, as the other boys climbed into the convertible. By this time it was almost dusk. âWeâll have to show our appreciation to you by working harder than ever to locate the demiculverin.â

Just then they were startled by a sound that resembled a low, muffled groan.

Frank looked around. âWhat was that?â

âJust the wind in the trees, I guess,â Bowden replied as he waved and drove off.

âWell, one thing seems certain,â Frank remarked as he pulled out onto the road. âBowden didnât know anything about the attacks on us.â

âOn the other hand,â said Joe, âthose thugs may have been in his employ and he drove out here to see if they had carried out instructions.â

âIf youâre right,â said Frank, âhe sure got a surprise. And say, what about Gorman? I guess he didnât come to the shack after all.â

âBut sent those thugs instead,â Joe said.

âListen, you just said it was Bowden.â

âSure I did. I donât know whatâs going on. Iâm completely baffled. And now, Chet, tell us what happened to you.â

âHereâs the story. It all began when I put an ad in the paper.â

âFor what?â Joe asked.

âSkin-diving equipment. I wanted to buy some secondhand. Well, this morning a fellow came out to the farm to see me.â

âBy the name of Gil,â Frank said. âIola told us. What was his last name?â

âI didnât ask him,â Chet said. âI was too excited. You see, he told me he represented a man who was willing to sell his equipment cheap.â

âWhat happened then?â

âI was out at our pool when he arrived. His car was parked down the road and he offered to drive me to the manâs house to look at the gear. Since he was in a hurry, I hopped in without taking time to change.â

âWhat then?â Frank asked.

Chet related that the boy had stopped the car in a wooded section which he said led to the house. âAs soon as I stepped out, a stocky, masked man jumped from behind a tree. In a flash he had me tied up and blindfolded,â

âThen what?â Frank asked.

âWhile I was lying there in the rain, he said, âWhat did you do with the cutlass?â â

â âWhat cutlass?â â I asked. âHe kicked me and said, âYou know which cutlass I mean.â

âI told him that I had been to an antique shop to buy one but had arrived too late. The man didnât have any left. I sure didnât want to tell him about the one you fellows have.â

âIâm glad you didnât,â said Joe. âChet, we were at that shop and heard the story. We think the character who bought all the cutlasses was Latsky.â

âWow! That sure complicates things.â

âWhy did you go to the shop?â Frank asked.

Chet smiled wanly. âI was hoping to get a clue for you on the sword Gorman and Bowden know about.â

âGood try,â said Joe. âGo on with your story.â

Chet scowled angrily at the recollection. âWhen I wouldnât tell that guy anything, he flew into a rage. I donât know what he hit me with but he sure kayoed me. From that time on I donât remember a thing until you found me in the gully.â

Just then the car reached the side road which led to the shack where Frank and Joe had been ambushed. Frank turned into it.

âHey, where you heading?â Chet asked. âI thought you were going to get me something to eat. Iâm weak.â

âTen minutes wonât make any difference,â Frank replied. âI just had an idea.â

âWell, it had better be good,â Chet grunted.

Frank said it was possible that the figure in the burlap sack at the shack had not been Chet. Why would his attackers have bothered to take him there and carry him off again?

âThe prisoner was probably someone elseâ maybe even Gorman,â Frank declared, âand he may still be there.â

âListen, fellows,â Chet protested. âI donât want to be captured again now!â

âYou wonât,â Frank said. âYouâll take the car key and hide in the trunk. Leave the lid open an inch. You can act as lookout and give us the old owl whistle if anyone approaches.â

âOkay, thatâs safe enough.â

Frank parked in the same spot as before. The Hardys put flashlights in their pockets and got out. The area ahead was in semidarkness, with the shack standing out like a black block silhouetted against the sky.

Frank and Joe moved cautiously, taking care not to step in the footprints that led away from the shack. Mingled with them were drag marks, no doubt made by the feet of the Hardys as the unconscious boys were removed from the building.

âYou take the front, Joe, and Iâll go around,â Frank suggested.

They separated. Finding no sign of an occupant, they finally beamed their flashlights through the windows. The shack was empty.

In swinging his light back, Joe became aware of something interesting a few feet away. Quickly he summoned his brother and pointed out a depression in the damp sand.

âSomeone was lying there,â he said, âFace down.â

âWell, it wasnât Chet,â Frank surmised. âFrom head to toe the length is a good six feet.â

âLook!â Joe exclaimed. âThereâs an initial here!â

The boys bent over a spot a few inches from the face mark in the sand. Scratched faintly was a letter.

âIt looks like a C,â Joe commented.

âOr perhaps a G,â Frank said. âIt could stand for Gorman.â

They assumed that the man, bound and gagged, had made the impression with the tip of his nose. A more careful search of the area revealed footprints and drag marks that indicated he had been taken into the shack, probably in a sack, then later carried off.

The boys trudged back to the shack and again looked at the face impression in the sand. Frank felt it belonged to Gorman.

âI wish there were some way to make sure,â Joe said.

âI think there is,â Frank replied. âLetâs make a mold of this face.â

The Hardys often made plaster molds of footprints and shoe prints. They kept the equipment for doing this in their workshop over the garage.

âWeâll have to come back early tomorrow,â Frank said. âIn the meantime, weâll protect the impression.â

He went into the shack and looked about for something to use as a cover. In one corner was an old box. He carried it outside, and placed it firmly over the sand impression.

âLetâs go!â Joe urged.

As they started back toward their car, the stillness was suddenly shattered by the mournful hoot of an owl: Chetâs signal that something had gone wrong.

The Hardys broke into a runt

CHAPTER XV

An Impostor

THE hooting was not repeated and the Hardys wondered if Chet were in trouble. They doubled their speed and quickly reached the convertible. No one was in sight.

Joe pulled up the trunk lid. Chet, inside, looked relieved.

âDid you hoot?â Joe asked him.

âI sure did. A couple of guys were here. I heard them coming through the woods, so I gave the signal.â

âWhere are they now?â Frank demanded.

âBoth of them ran back through the woods when they saw you coming.â

âWho were they?â

Chet said he did not know. It was too dark to see them well, but neither was the man who had knocked him out. From Chetâs description the Hardys concluded they might have been the men who had attacked them in the shack.

âThey didnât use any names,â said Chet, âbut they talked a lot.â He added that upon seeing the car, they had seemed worried, wondering how it got there. âThey decided that perhaps the police had brought it there and were using it as a decoy. Just then they saw you coming and beat it.â

âItâs a good thing they did,â said Frank, âor we might have had another battle on our hands.â

As the three boys started home, Chet gave a gigantic sneeze. âThose guysâll kill us one way or another,â he groaned. âBut Iâll probably die of pneumonia first.â

Joe wrapped a blanket from the rear seat around Chetâs shoulders, but the boy continued to sneeze all the way to the farm. By the time they entered the Morton driveway he was having chills.

âSorry,â said Frank. His conscience bothered him that they had not brought their pal home sooner.

âLook!â Joe exclaimed as they pulled up behind a police car. âChief Colligâs here now.â

Mrs. Morton and Iola were overjoyed to see that Chet was safe. Chetâs mother at once insisted that he take a hot shower and go to bed. She prepared a light supper, topped off with steaming lemonade.

In the meantime, the police chief listened in amazement as Frank and Joe related their experiences.

Chief Collig agreed with the Hardys that the case had assumed serious proportions. âTake it easy, fellows,â he advised. âIâll notify the State Police about that shack. Iâm sure theyâll want to station a man there.â

âJoe and I plan to make a plaster cast of the impression we found in the sand,â Frank told him. âWe thought it might be a good clue.â

âI doubt that it will work,â said the chief. âBut good luck. When are you going to do it?â

âVery early tomorrow morning.â

âIâll tell State Police Headquarters.â

The chief said he himself would put more men on the case and station a plainclothesman at the Morton farm. As he left the house, Mrs. Morton bustled into the living room to report that Chet had finally stopped sneezing. âHeâll be asleep in a few minutes,â she said.

Before Frank and Joe left they telephoned their home. Mrs. Hardy answered and was happy to hear that they had suffered no ill effects from their experiences that day.

When they arrived at the house, Aunt Gertrude greeted them with rapid-fire words of advice about staying away from mysterious shacks. âWhen youâve finished supper, go to bed and get a good nightâs sleep!â she added. âYou need it!â

âYouâre right,â said Joe. âFrank and I have a date at six tomorrow morning.â He told his mother and aunt what it was.

Mrs. Hardy sighed. âI suppose it wonât be dangerous for you to go if a State Police officer is there.â

âIâll call you,â Aunt Gertrude promised.

The next morning at five-thirty she roused her nephews. âHurry,â she commanded. âBreakfast is ready and cold eggs and toast are no good!â

The boys dressed quickly and went downstairs to find that their mother and aunt had prepared a hearty meal consisting of hot cereal, scrambled eggs, and cocoa.

âThe sooner you solve this mystery, the better!â Aunt Gertrude said as the boys ate. âIt has me on pins and needles.â

âToo bad,â said Joe. âBut I think weâll be closer to a solution when we make this death mask.â

âWhat on earth are you talking about? I didnât know someone wasââ

Frank and Joe laughed and calmed their auntâs fears. Then, becoming serious, Frank said he hoped the person whose face had made the impression in the sand was still alive.

Joe, pushing back his chair, said, âIâll carry the equipment from our lab, Frank, while you get the car out.â

Shortly after six oâclock the boys started off, promising to report back home by lunchtime.

âI wonât be here,â said Aunt Gertrude. âIâm going over to the state museum to a lecture. While there Iâll explain about the cutlasses. The trip will take me until ten tonight.â

âHappy landing, Aunty!â Joe said with a grin.

It was a pleasant ride in the early-morning fresh air and the sun stood bright over the horizon when they arrived at the dunes. At once they were challenged by a state trooper who stepped from the woods. Frank showed his driverâs license and introduced his brother. The man gave his name as Williams.

âChief Collig said youâd come,â he stated. âGo ahead. Thereâs another officer named Winn at the shack.â

Lugging the equipment for making the mold, Frank and Joe trekked to the small building and said hello to State Trooper Winn. âHas anyone been here since you came on duty?â Frank asked.

âNo. Not a soul.â

The box was still in place over the face in the sand. Joe lifted it. The impression was intact.

âCovering that was a good idea,â Trooper Winn remarked.

First, Frank used a spray gun and coated the imprint with a quick-hardening fluid. While he was doing this, Joe mixed plaster in a pail. Then he carefully poured it into the sand.

âWhen that sets, I hope weâll have a replica of the face, clear enough to be recognizable,â Frank said.

When the mold was hard, he lifted it from the sand and turned it over. The result was an indistinct blob. Only the chin line was clear.

âTough luck,â the trooper said. âThe sand dried out too much during the night.â

âStill Iâm certain itâs Gorman!â Frank said, pointing out the solid, jutting jaw. âHeâs a prisoner of those hoods!â

Quickly Joe explained the circumstances to the trooper.

âWill you tell all this to Williams?â the officer requested. âHeâll send out an alarm over the radio.â

âLetâs go!â Frank urged.

The Hardys gathered their implements and hurried back to the convertible. Frank told Trooper Williams of their discovery and he notified State Police Headquarters from his car, well hidden in the woods, to start a search for Gorman. When he finished speaking, Williams let Frank use the radio to contact Chief Collig. The officer said he would institute a local search.

âLetâs stop at Chetâs,â Joe proposed as they reached the main road.

âGood idea. Iâd like to know how he is. And heâll want to hear the result of our experiment.â

They found Chet in bed. There was no doubt he had a bad cold, but fortunately there was no sign of pneumonia.

The Hardys stayed with him an hour and brought him up to date on their morningâs activities.

Chet scratched his head. âWhere do you suppose Gorman is?â

Frank shrugged. âA prisoner some place of either Bowden or Latsky. I hope the police find him soon.â

Joe, eager to continue their search at Piratesâ Hill, rose and said, âTake it easy, Chet. Weâll let you know if anything new turns up.â

It was noon when Frank and Joe reached home, Mrs. Hardy had a tasty lunch ready. They ate quickly and soon were ready to go out again.

âIâd like to search until itâs too dark to dig,â said Joe. âLetâs take some supper with us.â

Frank agreed. They told their mother they would be back around nine and drove to Piratesâ Hill.

Working in the damp sand proved to be a hot, arduous task, and before they ate their sandwiches, the boys went swimming. When the sun was about to set, they packed their tools and left.

âNot one clue to that demiculverin,â Joe said in disgust.

âBut weâre not giving up!â Frank declared.

Exactly at nine oâclock the Hardysâ car hummed up Elm Street and Frank turned into their driveway. They noticed a dark-blue sedan parked in front of their home.

âA visitor,â Joe said. âWonder who it is.â

Pulling up in front of the garage, they got out and went in through the kitchen.

Mrs. Hardy greeted them. âYou just missed a friend.â

âWho was it?â Frank asked.

âTony Pritoâs cousin Ken,â Mrs. Hardy replied. âHe came for the cutlass, as you requested.â

âWhat!â Frank cried in alarm.

âTony phoned a little while ago. Said you were at his house and had told them about the sword. Ken would come over and pick it up in a few minutes. So I wrapped it in newspaper and gave it to him. He just drove off in a dark-blue car.â

âMother!â Joe cried out. âThat man was an impostor! We werenât there and Tony has no cousin Ken!â

Mrs. Hardy sank into a chair. âOh, how dreadful!â she wailed.

Frank put an arm around her. âDonât worry. Weâll go and find that man!â To Joe he said, âWe must get that cutlass back! There might be a clue in it that will tell us what Latsky, Bowden, and Gorman are really searching for.â

The boys dashed to their convertible and sped after the thief.

âThere he goes!â Joe cried as Frank turned the next corner.

The convertible leaped ahead. Five blocks farther on, the driver of the blue sedan, apparently unaware that he was being followed, stopped for a red light. Frank quickly pulled alongside on his left. The man at the wheel wore a black motorcycle jacket.

âLatsky!â Joe exclaimed.

On the seat alongside the driver Joe saw a narrow, newspaper-wrapped package. The cutlass!

As Joe flung open the door and hopped out, the man turned to look at the boys. His swarthy face twisted into an ugly sneer.

âWeâve got you, Latsky!â Joe cried, quickly reaching for the door handle.

But the ex-convict was quicker. Gunning his motor, he shot across the street against the red light. Joe was flung to the pavement.

CHAPTER XVI

The Wreck

BRAKES screeched as oncoming cars tried to avoid colliding with Latsky. Joe picked himself up and jumped into the convertible. Frank, gritting his teeth impatiently, waited for the signal to change. When it clicked to green, he took off in hot pursuit of the fleeing sedan.

âI hope Latsky sticks to the main highways,â Joe said. âWith his head start, weâll have a tough time catching him if he turns into a side street.â

Reaching the outskirts of the older section of Bayport, Frank increased his speed. Suddenly, going over a small rise, the boys saw the red glow of rear lights. A car swung to the left into a T-intersection highway that circled wide to the right, by-passing the outlying residential section.

âItâs Latsky!â Joe shouted.

At almost the same moment they heard the wailing of a siren close behind them.

âA police car,â Joe said. âI guess the officer thinks weâre speeding. Slow down, Frank.â

The boy eased his foot off the accelerator and the squad car pulled alongside. Chief Collig himself was at the wheel. âWhereâs the fire, fellows?â

âWeâre after Latsky,â Frank explained, and quickly told of their chase.

âIâll lead the way!â the chief said.

Though the officer drove a special high-powered vehicle, Joe doubted that he could catch the fleeing car. Latsky had too much of a head start. âFrank,â he suggested, âhow about taking the shortcut past the old Pell farm? Then weâll come back onto the main highway and throw up a roadblock.â

âGreat! Iâll try it.â

Frank whirled to the right at the next lane, roared over a narrow macadam road for a mile, and then turned left into another dirt lane. Minutes later he zoomed onto the highway again.

âHere he comes!â Joe cried out as two headlights flashed over a low hill behind them. In the distance the whine of the police siren sounded.

Frank slammed on his brakes and angled the convertible across the road, so that the red lights blinked a warning to stop. Both boys jumped out, concealing themselves behind a tree along the roadside.

âWow!â Joe whispered. âLatsky and the chief must be doing ninety!â

The next second there was a squeal of rubber on concrete. Latsky had spotted the roadblock and jammed on the brakes.

âHeâs out of control!â Frank cried.

The oncoming car headed wildly for the tree behind which the Hardys had taken cover. As they ran, the car bounced off the tree and screeched across the road into a field, where it overturned.

Joe and Frank sped toward the wreck, flashlights in hand. While they were still some distance away they saw Latsky, carrying the cutlass, stumble from the car. Dazed for the moment, the man staggered, but quickly regained his equilibrium and dashed off into the darkness of a woods.

At that moment Chief Collig roared up and stopped. Seeing the flashlights, he got out and hurried across the field. The Hardys were trying to pick up Latskyâs footprints.

âAm I seeing things?â the officer cried out. âHow did you get here? And whatâs going on?â

âShortcut,â Joe said. âWe set up a roadblock and stopped Latsky, but he ran away.â

Swinging the bright beams of their flashlights in the woods, the trio followed the footprints. They led to a wide brook.

âLatskyâs clever,â Chief Collig remarked. âHe must have entered the water and walked either up- or downstream.â

The Hardys offered to take one direction while the chief took the other, but Collig shook his head. âWeâll never pick up his trail in the dark. Iâll send out an alert on the radio.â

The three left the woods. While Collig went ahead to phone, the Hardys paused to look over the wreck of Latskyâs car.

âHe dropped the cutlass!â Joe cried out suddenly as his flashlight reflected on the shining steel blade.

Grabbing it, he hurried with Frank to the police car. Chief Collig was just concluding his conversation. He was delighted to hear that the boys had retrieved their ancient sword, then said, âMy men are starting out now to track down Latsky. By the way, that wrecked car was stolen. Too bad for the owner.â

Soon a tow truck arrived to haul the smashed sedan to the police garage. The Hardys said good-by to the chief, and with the cutlass, started home to give it a close examination.

After telling their mother and Aunt Gertrude that they had retrieved the weapon, Frank and Joe went directly to their laboratory over the garage. Under a powerful work lamp they quickly examined the blade. On one side was etched the name of the maker, Montoya.

âThereâs probably more,â Joe said excitedly, getting out bottles of chemicals with which to clean off the metal. Every inch of the fine Damascus steel blade was inspected for other markings or hidden writing. There were none.

âThe maker of this cutlass must have considered it too fine to mark,â Joe said. Old as it was, the sword still had a keen edge.

Next, the handle was cleaned. Every seed pearl in the design was intact, and the gold leaf was still in place.

âLetâs examine that handle closely,â Frank suggested, getting a magnifying glass.

There was a heavy, richly encrusted leaf scroll pattern. The Hardys scrutinized this minutely to see if it concealed any gems or contraband, but without success.

âI still think there might be something in this handle,â Frank said stubbornly. âLetâs try that special magnifying glass of Dadâs.â

âGood idea!â said Joe. âIâll get it.â

He ran back to the house and in a few minutes returned with the extra-powerful glass.

Frank focused it over the handle inch by inch. Suddenly his face lighted up. âLook here, Joe!â he exclaimed, pointing.

Looking through the magnifier, Joe saw a tiny line which had been cleverly worked into the leaf pattern.

With the thin blade of a knife, Frank tried to force the crack open, but it was impossible.

âMaybe thereâs a spring hidden somewhere in the handle,â Joe suggested. âLet me try it.â

Frank handed him the cutlass and Joe bent over it intently. He pressed each tiny leaf but the crack did not widen.

âA spring could be connected with the blade,â Frank mused. âBut how?â

âPerhaps the spring is rusted after all these years,â Joe said. âIâll try hitting the blade on something.â

He looked around the laboratory and found a slab of stone left over from a previous experiment. Grasping the handle of the cutlass firmly, he jabbed the tip against the hard surface.

Click! The crack widened a full inch!

The boys were jubilant. Frank bent down and examined the sword.

âThe tip contains a tiny mechanism,â he said after a momentâs scrutiny. âIt must extend through the blade all the way to the handle. Very ingenious!â

He inspected the opening and reached into it with his thumb and forefinger.

âAnything there?â Joe asked.

âWait a minuteââ

There was a soft crinkling noise. âI can feel something,â Frank said. âHere it comes.â

Gingerly he pulled out a small piece of ancient parchment. It was folded up into a compact wad.

Frank carefully smoothed it out. âThereâs writing on it!â he exclaimed excitedly.

CHAPTER XVII

Gunnerâs Tools

âFRANK, this message is written in what seems to me ancient Spanish,â Joe said. âI canât make it out.â

âWhatever it says must be mighty important,â Frank concluded, âor the writer wouldnât have hidden the message.â

âAnd Bowden and Gorman and Latsky must think so too,â Joe added.

Happy but weary, the boys went to bed, the cutlass safely tucked under Frankâs mattress.

At breakfast the next morning they showed the old parchment to their mother and Aunt Gertrude. All were bending over it excitedly when Chet walked in.

âWow!â he said when he heard the newest development in the mystery. âYou sure are good detectives.â

At that moment the phone rang. âIâll take it,â Joe offered, hoping the caller would be Mr. Hardy.

The other boys followed him to the phone and stood near as he spoke.

Placing his hand over the mouthpiece, Joe whispered to Chet and Frank, âItâs Bowden!â

He held the receiver a distance from his ear to let them hear the conversation. Bowden said that Gorman had been arrested in St. Louis while traveling under an assumed name.

âA friend of mine on the St. Louis police force, knowing I was interested, just phoned me,â Bowden continued. âI guess we can go about locating the cannon without any interference from Gorman.â

The boys were skeptical of the story.

To Bowden, Joe merely said, âThank you for the information. Weâre working hard on the case.â

The man told Joe he would let the Hardys know if anything further developed. He was about to hang up when Chet burst out:

âTell him weâve found the clue in the cutlass!â

Frank gave Chet a warning look, but too late. Bowdenâs next words were, âI heard what someone just said. Whatâs it all about?â

âOh, nothing, really,â Joe replied. âJust a story we heard and havenât had time to check out yet.â

âOh.â Bowden seemed to be thinking hard, but did not pursue the matter.

After Joe hung up, Chet apologized for revealing the news. Frank and Joe were disturbed but assured him that by working fast they would get to the bottom of the mystery and no harm would result from Chetâs slip.

âNow if we could only think of someone who might translate the message on the parchment,â Frank said.

âLetâs try our Spanish teacher, Miss Kelly,â Joe suggested. âIf sheââ

At that moment the doorbell rang. Aunt Gertrude went to answer it and presently came back with a telegram.

âItâs for you,â she said and handed the message over to Frank.

âFrom Dad,â the boy said as he unfolded the telegram. âAnd, Joe, itâs in code!â

âLetâs go upstairs and decipher it,â Joe said. The Hardys dashed to their fatherâs study and removed Mr. Hardyâs code book from his filing cabinet. Quickly they decoded the message:

BEWARE DOUBLE-CROSSING BY BOWDEN!

âDouble-crossing!â Frank echoed the warning in the telegram. âDad must have further information about Bowden.â

âI wish he had told us more,â Joe said as they returned to the first floor with the news of Mr. Hardyâs message. Instantly Mrs. Hardy and Aunt Gertrude became alarmed.

The boys, fearful that their mother might insist they abandon their sleuthing, promised to take extra precautions from now on.

âIf Bowden still doesnât suspect that we mistrust him,â Frank said, âweâll have the advantage.â

âWhich we hope to hold until Dad returns,â Joe added.

Chet whistled. âWell, count me out of any more trouble,â he said. âIâm off for home. Let me know what that foreign parchment says, will you?â

After Chet had chugged off in his jalopy, Frank suggested that they call on Miss Kelly to see if she could translate the message found in the cutlass.

âLetâs stop at police headquarters on the way,â Joe said. âWeâll check Bowdenâs story about Gormanâs arrest.â

With the parchment tucked securely in Frankâs inner pocket, they drove to headquarters. There the sergeant in charge promised to check with St. Louis about the alleged arrest. Before leaving, Frank asked if the man named Guinness who had exploded the fireworks had been caught. The officer shook his head.

âPlease let us know what you find out about Gorman,â Joe said as they walked out.

Frank drove across Bayport to the small cottage where Miss Kelly lived. She was a pleasant middle-aged woman, well liked by her students.

âWe wondered if you could help us solve a mystery,â Joe said as they all sat down in her cool, attractive living room.

âBy the expressions on your faces I thought you must be working on one,â Miss Kelly said,

Frank produced the parchment. âIs this Spanish, and can you translate it?â

The teacher studied the scrawled writing for a moment. âNo,â she said. âThis is written in Portuguese, old-fashioned Portuguese at that. But I believe Mrs. Vasquez might be able to help you.â

Handing back the paper, she explained that Mrs. Vasquez was an elderly Portuguese woman, the mother of a fishing boat captain.

âShe isnât well and doesnât get up until afternoon,â Miss Kelly said, âbut Iâm sure if you go see her after lunch, she would help you. Iâll give you her address.â

She looked in the telephone directory and wrote it down. The boys thanked her and left.

âIf we canât get the message translated until after lunch,â Joe said, âletâs go out to Piratesâ Hill and call on Sergeant Tilton. Maybe he can give us some idea of where to dig.â

âOkay,â Frank agreed. âWe havenât had any luck ourselves.â

âThis hereâs a gunnerâs scraper,â Tilton replied

They drove to Tiltonâs cottage. The sergeant, dressed in dungarees and a coonskin cap, was working in his small flower garden.

He was in high spirits. âHi there, boys!â he yelled.

âGood morning, Sergeant Tilton,â Frank replied. âWeâve come to do some more digging for that cannon.â

âWe thought maybe you could show us where you think it should be,â Joe added.

âWell, now, let me see,â the man drawled as he came toward them. âSuppose I walk around the place with you.â He grabbed up a folding canvas chair.

When they had gone about fifty yards along the dunes, he stopped and scratched his head. âAccordinâ to my system of reckoninâ, the gun must have been located just aboutâNo.â He moved a few steps to his left. âJust about here.â

Sergeant Tilton lighted an old pipe and seated himself comfortably on his folding chair, and the boys started digging. He told them story after story of his Army adventures while they spaded deep through the white sand.

âHold everything!â Joe called some time later. He was standing waist-deep in a hole. âIâve found something!â

He bent over and came up with a queer-looking gadget. âWhat would this be?â he asked, handing it to the sergeant.

Tilton examined it carefully. âThis hereâs a gunnerâs scraper,â he replied.

âProbably belonged to the same gear as that pick Chet found the other day,â Frank whispered to Joe.

Protected by the sand, the scraper had withstood the ravages of time better than the pick had.

âThe cannonâs just got to be near here!â Joe declared excitedly.

âThatâs right, my boy.â Tilton wore a knowing look as he gave the scraper back to Joe and resumed puffing on his pipe. âDonât stop digginâ, lads.â He blew out a small cloud of smoke.

Ten minutes later Frank spaded loose a six-foot-long wooden pole fixed at one end with an iron blade. As he handed it to Tilton, the old sergeant exclaimed, âItâs a handspike! You must be gettinâ close!â

CHAPTER XVIII

Guarding a Discovery

THOUGH eager to continue the search, Frank and Joe paused a moment.

âWhat was that strange-looking pole used for?â Frank asked Sergeant Tilton.

âTo manhandle the heavy cannon,â he replied. âWith this tool, the gunners could move the carriage, or lift the breech of the gun, so they could adjust the elevatinâ screw.â

Jubilantly expectant, the Hardys dug deeper into the sand. But nothing further came to light.

Finally Frank straightened up. âJoe,â he said, âitâs noon. Weâd better let our search go for now. You know we have an errand in town.â

Joe had almost forgotten their plan to call on Mrs. Vasquez and have the parchment translated. âYouâre right, Frank.â He asked Sergeant Tilton to keep the spike and pole until the boys called for them. Then they quickly covered the hole with branches and sand, took their tools, and started back.

After stopping for a quick lunch, the Hardys drove directly to Mrs. Vasquezâs home. Her daughter-in-law answered their knock, and when Frank explained the boysâ mission, they were ushered inside.

A white-haired old lady with black eyes stared curiously at them from a rocking chair. She smiled, adjusted her black shawl, and motioned for them to be seated.

âMother doesnât speak much English,â the daughter-in-law said, âbut Iâll translate.â

The Vasquezes spoke rapidly in Portuguese, then the old lady leaned back in her rocking chair and read the parchment. When she looked up, more words in Portuguese followed.

âMama says this message gives directions.â

âFor what?â Frankâs heart pounded.

Again there was a rapid exchange, then the younger woman smiled. âDirections to a cannon. Iâll write it all down.â

As Mrs. Vasquez spoke, her daughter-in-law translated and wrote:

On high rock Alaqua Cove due east setting sun first day July is treasure cannon. Demiculverin.

The younger woman smiled. âDoes this mean anything to you? Where is Alaqua Cove?â

âThat was an old Indian name for Bayport, I-think,â Frank replied. âThanks a million. And, please, will you keep this a secret?â

âOh, yes. Mama and I will say nothing. Iâm glad we could help you.â

Frank and Joe said good-by and left the house. They were grinning ecstatically.

âAt last weâre going to solve this mystery!â Joe said.

âAnd the time of year is perfect,â Frank added. âWeâre only about a week over the designated date. That shouldnât give us much trouble.â

On reaching Piratesâ Hill with their digging tools, Joe became restless, âI hate to wait until sunset. Canât we start?â

âSure. Weâve been here so much the past few days I can tell you exactly where the sun has been setting.â

Frank pointed to a distant church spire. âRight there.â He took a compass from his pocket and moved about until his back was due east of the spire. âThe cannon should be somewhere along this line,â he said and shuffled through the sand.

âThe directions said âhigh rock,â â Joe re minded him. âThere are rocks under the sand. Letâs try the highest point on this line.â

The boys set to work. All afternoon they dug furiously. Finally, as the sun was about to set, Frankâs spade struck metal!

âJoe,â he cried, âthis must be it!â

A moment later they uncovered the curve of a barrel, and judging from its dimensions, they were convinced that this was the Spanish demiculverin for which they had been searching.

âSuccess!â Frank exclaimed.

Then suddenly he sobered. âWeâd better be careful,â he said. âSomebody might be spying on us.â

âYouâre right,â Joe agreed. âLetâs cover up the gun again. Itâs getting dark and we wonât be able to dig the whole thing up tonight.â

Shoveling quickly they concealed the valuable discovery until they could come back the next day and uncover it completely. Then, to bewilder any prying eyes, the Hardys decided to make small excavations at other spots.

A short time later two figures appeared over the dunes. Tony Prito and Chet!

âWe came out in the Napoli,â Tony said, âFigured youâd be here. We called your house and your mother gave us a message for you.â

âAbout Gorman,â Chet added. âThe police left word that heâs not in St. Louis.â

âJust as we suspected,â Joe said.

Then Frank, in a low voice, told about finding the demiculverin. âWow!â Chet exploded.

Tony congratulated his friends and asked what their next move would be.

âWeâll dig up the whole cannon tomorrow,â Frank replied.

âI sure wish we could stay here tonight and get an early start,â Joe said. âSay, why donât we camp out and stand guard over the cannon?â

âSwell idea,â Frank agreed.

Tony offered to go back in the Hardysâ car and pick up a tent, sleeping bags, and food.

âIâll call your folks and tell them,â he promised.

Two hours later the camp on Piratesâ Hill was ready, with the tent pitched on the cannon site. As the stars came out, the Hardys and Chet crawled into their shelter. Tony had volunteered to stand guard first and posted himself outside the tent flap.

At eleven oâclock he became aware of an approaching figure. Instantly he awoke his sleeping pals. They waited tensely until the person was almost within reach.

âGet him!â Joe cried suddenly.

The campers lunged out of the shelter. Just as Joe was about to tackle the figure, he recognized him.

âSergeant Tilton!â he exclaimed.

âSo itâs you,â drawled the elderly man. He explained that he had spotted their flashlights and had come to see who his neighbors were.

Knowing that the sergeant was inclined to gossip, the boys decided to keep their finding of the cannon to themselves. They chatted casually with Tilton, telling him they had set up camp to be ready for some sleuthing early in the morning.

âWell,â the sergeant said finally, âI reckon Iâd better git back to my shack. I suspect youâll all be snorinâ soon.â He chuckled and walked off.

The rest of the night passed quietly, with the boys rotating the guard watches as they had planned earlier. By six oâclock they were up and preparing breakfast. After eating, the Hardys and Tony started work under the tent, with Chet acting as lookout.

Within an hour the three had dug a deep pit and uncovered the entire demiculverin. The old fieldpiece appeared to be in good condition.

âWhat a beauty!â Frank exclaimed.

âAnd look at this number on it!â Joe cried out. Engraved on the barrel were the numerals 8-4-20. âIt must be a code for this type. Letâs find out what it stands for.â

Leaving Chet and Tony on guard, the Hardys went home in the convertible to check through their fatherâs books on cannons. Joeâs hunch that the numerals might be a code led to nothing. They read on.

Suddenly Frank exclaimed, âI get it! An eight-pound ball and four pounds of powder.â

âAnd twenty degrees of elevation!â Joe beamed.

Hearing the excited conversation of the boys, Mrs. Hardy looked into the room and asked, âHave you found out something interesting?â

âSunken treasure!â Joe exulted. âA ball shot from the demiculverin probably marks the spot where the old merchantman was sunk by the pirates in that Battle of Bayport!â

Mrs. Hardy was astounded. She started to praise her sons when the front doorbell rang. Frank hurried down to answer it, Opening the door, he blinked in amazement.

Bowden!

As Frank recovered from his surprise, he said, âCome in,â and called loudly over his shoulder, âJoe! Mr. Bowdenâs here!â

Joe came down the stairs like a streak of lightning. âWhatâs up now?â he wondered.

Bowden smiled. âCanât stay but a few minutes. Good news travels fast. I understand youâve located the cannon I asked you to find!â

The Hardys were dumbfounded.

âIâll have the money for you shortly for solving my case,â Bowden continued. âAnd Iâll send a truck out to Piratesâ Hill tomorrow to pick up the demiculverin.â

CHAPTER XIX

Human Targets

FRANK and Joe were speechless for a moment. Then Frank asked, âHow did you hear we found a cannon?â

The manâs reply proved to be another bombshell. âI was out there and your friends told me.â

Frankâs mind whirled. He looked at Joe and realized his brother was thinking the same thing. Whatever Bowdenâs real reason was for wanting the ancient cannon, they were going to keep it from him until further word arrived from their father or the police.

Bowden again seemed to be one step ahead of them. âYou donât know it yet, but I own Piratesâ Hill.â

âWhat?â Frank asked, thunderstruck.

Bowden pulled several documents from his pocket. One was a certificate of sale, another a government release, and the third a letter with a notary-public seal. This stated that Bowden had a right to anything found on Piratesâ Hill.

âThey certainly look authentic,â Frank said, but realized the papers could be clever forgeries.

Mr. Hardyâs warning to his sons indicated that Bowden was probably a confidence man. It was possible that he had accomplices who could imitate signatures and print fake documents.

âI must get in touch with Dad about this,â Frank said to himself.

He and Joe knew that the only course was not to let Bowden know of their suspicions. But Joe winced as his brother spoke.

âIt looks as if the hill is yours all right, Mr. Bowden. If thereâs a cannon on it, there may be other treasures, too.â

Frankâs assurance pleased Bowden. âI hope youâre right. And Iâm glad you see the whole thing my way. To tell the truth, I thought you might want the old cannon yourselves. Accept my congratulations for a grand job.â

After he left, Frank said, âIâll bet those papers Bowden showed us are fake!â

Joe nodded. âWeâd better let Dad know about this right away.â

Since it was not possible to reach Mr. Hardy by telephone, they composed a telegram in code, mentioning the fact that the cannon had been found and Bowden was claiming it. Frank phoned the message to the telegraph office.

âI hope this information will bring Dad up here,â Joe said. âBowden is crooked, Frank. We canât just hand him the cannon.â

âOf course not. But donât forget, Joe, digging out the sand around the demiculverin so it can be lifted, and lugging the two tons of iron over the sand may take days. Maybe something will happen in the meantime to stop Bowden.â

âLetâs hope so,â said Joe. âWell, how about doing some computing on those numbers we found on the cannon?â

âGood thought.â The boys quickly discovered, however, that they were unable to solve the gunnery problem. Frank suggested that they drive over to see Mr. Rowe, head of the Mathematics Department at Bayport High. âHeâs teaching summer school. Iâm sure heâll be there now.â

They set off for Bayport High and found Mr. Rowe. Intrigued by the problem, he went to work, filling several sheets of paper with calculations. At last he said:

âThe cannon ball would land two thousand yards away, if trained and elevated at precisely the angle given in my figures.â

Frank and Joe thanked him, then hurried to their car. On the way back to Piratesâ Hill, Frank remarked that if the demiculverin had not been moved, and currents had not shifted the ship, the treasure should be easy to locate.

Joe grinned. âLetâs measure two thousand yards from the cannon, then hand it over to Bowden with our compliments!â

Frank reminded his brother that whatever their plans, they had to work fast. He parked off the shore road as before and the Hardys ran up to Chet and Tony.

Suddenly Joe stopped short. Grabbing Frank by the arm, he cried out, âLook! Thereâs Bowden again!â

At the site of the cannon, Bowden and Sergeant Tilton were talking to Chet and Tony.

âGood-by to our plan,â Joe said.

âMaybe not,â Frank remarked. âIt might take him some time to catch on to the whole thing.â

Chet and Tony dashed up to meet the boys and whispered that after Frank and Joe had gone back to town, they had continued digging. The two men had caught them off guard.

âYou can see the cannon very plainly now,â Tony said. âWe thought weâd surprise you and remove all the sand from the front of it.â

âThanks,â Joe said. âIt was a nice idea.â

Frank quickly related Bowdenâs visit to the house. Tony frowned. âMaybe that gossipy Sergeant Tilton told him we were here.â

As the group reached the men, the Hardys received only a nod from Bowden, but the genial old sergeant began to talk excitedly. He explained that at Bowdenâs request he was preparing a charge similar to the one he used to test the mortar in the town square at Bayport.

In spite of Bowdenâs efforts to signal him to keep quiet, Tilton continued, âAnâ Iâm goinâ to test the strength oâ the barrel fer Mr. Bowden. He wants to be sure itâll be safe fer him to fire off durinâ that there exposition in Florida.â

âAre you sure you arenât planning to shoot a cannon ball?â Joe asked suspiciously.

The old gunner protested in disgust. âOf course not. Thatâd be against the law. Iâd have to git permission from the Coast Guard.â

âThatâs right,â said Joe, eying Bowden to watch his reaction. But the man showed none.

As the boys looked on, Tilton prepared the powder charge and fired the gun. A thunderous boom followed. As the smoke cleared, he rushed back to inspect the cannon.

âShe stood up fine!â he exclaimed.

âWell, thanks, Sergeant,â said Bowden. âI guess the cannon will do for the pageant. Iâll see you later,â he added as he walked away.

The old man began running his hands along the cannon and talking to himself. âGreat piece oâ work,â he declared. He turned to Frank and Joe. âIâd like to tell you a bit about this.â

âWeâd like to hear it a little later,â said Frank.

The Hardys were eager to locate the old sunken merchantman. When their friends agreed to help, Frank asked Chet to drive to their boathouse in the convertible to pick up the aqualung diving gear. Tony offered the use of the Napoli from which to work.

When Chet reached the road, Bowden was just driving away. As his car gathered speed Chet saw a piece of paper blow out the window. Picking it up, he examined it curiously.

âWhy, itâs a stock certificate of the Copper Slope Mining Company. It must be valuable,â he mused. âIâd better return it to Bowden.â

Suddenly he recalled what Frank and Joe had told him about Bowden selling stock to a man in Taylorville. âThis certificate might be phony!â

Chet decided to leave the certificate at the Hardysâ home for inspection later on. He got into the convertible and drove to Bayport.

Out on Piratesâ Hill, Frank was saying to the old sergeant, âNow tell us about this cannon.â

Tilton beamed. âFiring a gun like this here one is a pretty risky thing.â

He went on to explain that the demiculverin most likely had been used at some Spanish colonial fort before the pirates had captured it. The normal life of such a cannon was twelve hundred rounds. But at an outpost, where it was hard to get new weapons, a piece was always fired many rounds beyond that figure, increasing the danger of explosion with each burst.

âWhen cracks develop âround the vent or in the bore,â Tilton said, âyou got to be careful. The muzzle sometimes blows clean offâem!â

Digging away more sand, the boys found that the cannon was mounted on a mahogany four-wheeled truck carriage used on eighteenth-century ships and garrison guns. It was covered with beautiful leaf designs, wrought in iron.

âLook!â Joe cried. âItâs chained to a boulder.â

This convinced the Hardys that they had been right in their deductions. The cannon was placed so that a ball fired from it would strike one particular place in the ocean!

The boys took sights along the gun barrel and checked them with their compass. The barrel pointed due east. This would make it easy to estimate the approximate spot where the treasure should be. They chafed under the necessity of awaiting Chetâs return.

âWhat you fellows aiminâ to do, now that you got this mystery solved?â Tilton asked them.

âLook for another case, I guess,â Joe replied. âRight now weâre going for a swim.â To himself he added, âAnd look for the buried treasure!â

âHm!â said Tilton. âI ainât been in the water fer nigh onto thirty years.â

He climbed off the gun emplacement just as Chet came hurrying across the sand without the diving gear.

âSomethingâs up!â Joe declared.

Puffing, Chet halted. âFrankâJoe, Iâve got big news. Chief Collig phoned your home. Latskyâs been captured!â

âHonestly?â Frank exclaimed, hardly daring to believe it was true.

âGreat!â Joe cried out. âHow?â

âHe finally returned to the cabin. Seems he had money buried near there and had run out of funds,â Chet replied. âThe police had no trouble nabbing him.â

Joe grinned. âLatskyâll be back in the penitentiary for a long stretch.â

After a brief discussion about him, Frank looked at Chet. âIn all the excitement I guess you forgot our diving gear.â

Chet laughed and told him it was in the car. The boys said good-by to Tilton and went to pick up the equipment. On the way Chet told the others about the stock certificate Bowden had lost and that Mrs. Hardy now had it.

âSwell work, Chet!â Frank exclaimed.

The diving gear was carried to the beach. As the boys waded out to the Napoli, Joe reviewed what they would do. Tony and Chet were to remain aboard the boat, while Frank and Joe did the diving.

âWeâll work by dead reckoning on the first attempt,â Joe told his pals. âFrank and I will go over the side at the estimated distance from the shore.â

âLetâs get started,â Tony urged.

âHold on!â Frank said. âI think weâre foolish to leave the cannon unguarded with Bowden loose. No telling what he may try to pull.â

âWhat do you suggest?â Joe asked.

âThat one of us go back and watch. If Bowden comes, our guard can signal and weâll get to the hill in a hurry.â

âIâll do it,â Chet offered. âBut how?â

Tony took a large yellow bandanna and a clean white rag out of the boatâs locker. He handed them to Chet. âWigwag with these,â he said.

âAnd be sure to hide behind a dune,â Frank cautioned, âso Bowden wonât see you.â

The others climbed into the motorboat and Tony started the engine. Frank and Joe gave directions to the site of the sunken treasure, using the church spire as a landmark and keeping on a course due east. Tony steered the Napoli carefully while Frank and Joe tried to estimate a distance of two thousand yards from shore.

âStop!â Frank commanded presently. âUnless all our reckoning is wrong, the treasure ship must be directly below us.â

There was silence for a few moments as the full import of Frankâs words struck them all. They might be about to make an intriguing find!

âLetâs go down!â Joe urged his brother.

The Hardys donned their gear and climbed over the side.

Tony, watching Chet intently, suddenly cried out, âWait, fellows! Chet is signaling!â

Back on Piratesâ Hill their pal had seen Bowden sneaking up to the cannon. As he watched the man, terror struck his heart. Bowden was ramming a charge of powder into the ancient gun. Then he inserted a cannon ball into the muzzle!

All this time Chet was wigwagging. The boys on the water interpreted, âBowden here. Look out forââ

The missile ready, Bowden ran to the back of the cannon and inserted a fuse into the vent hole. Chetâs hands were shaking with fright. Bowden flicked on his lighter and held it to the fuse, then stepped back.

âRun!â Chet signaled.

Boom!

With a shuddering detonation the demiculverin sent the deadly ball directly toward the Napoli!

CHAPTER XX

Diversâ Reward

WHAM! Smack!

The cannon ball hit the Napoli a second after the boys had flung themselves away from it. Spray and debris flew in every direction.

The Hardys, only a few feet away, were knocked unconscious by the concussion. Tony, unhurt, was worried about his companions. He realized that in their diving equipment they would float and could breathe even if they were unconscious. However, he was afraid that his friends might not have survived the shock.

Catching up to Joe, he was just in time to see the boy move his arms. He was alive!

âThank goodness!â Tony said to himself. Then he went to find Frank. To his relief, he too had regained consciousness. Frank removed the mouthpiece of the air hose and took a deep breath.

âDo you think Bowden meant to kill us?â Tony asked.

âIt certainly looks that way.â

Just then Joe swam over to them. One glance at the Napoli told the three boys that it was doomed.

âToo bad,â said Joe.

âGuess weâll have to swim to shore. Stick close to us, Tony,â Frank advised.

The boys struck out toward the distant beach, but they had not swum fifty yards when they heard the roar of a motor.

âA Coast Guard boat!â Joe called out.

The launch circled to pick them up. The young lieutenant in charge, Ted Newgate, was glad to see that they were all right.

âWe heard the report of a cannon and came to investigate,â he said as they were hauled aboard. âWhatâs going on here?â

âSomeone on the hill tried to blow us out of the water,â Joe answered. âI want to get to shore as fast as possible and find him.â

The powerful motor kicked up foam as the boat headed toward land. Nearing Piratesâ Hill, Frank gave a cry. âJoe, thereâs Dad on the beach with Chief Collig and Chet.â

Joe shaded his eyes. âAnd look whoâs hand-cuffed to Collig! Bowden!â

Quickly the boys told the lieutenant about the secret of Piratesâ Hill. The young man was amazed and congratulated them on their good work. Then he put them ashore in the launchâs gig. When the bow hit the sand, Frank and Joe raced across the beach to greet their father, a handsome man in his early forties.

âAre you all right?â he asked.

âWeâre okay, Dad, but no thanks to Bowden,â Frank replied.

The police chief said, âYou can thank your lucky stars youâre still here to tell the story. The charge against Bowden will be assault and battery with intent to kill. And the Coast Guard will have something to say about his firing without permission.â

Bowden looked completely beaten. The police chief explained that the man had stolen a cannon ball from the town square, hoping to use it to locate the sunken merchantman.

âWhen he spotted you fellows out there, Bowden saw a good chance to eliminate you from the race for the treasure.â

Joe glared at the prisoner. âWe didnât trust you, but we didnât think you were a killer.â

âIf the repercussion from that old cannon hadnât knocked him out, he would have got away before your dad and I showed up,â Collig stated. âHe was armed, so Chet wouldnât have had a chance to stop him. Well, Bowden will get a long stretch in prison to pay for his crimes.â

Frank asked his father how he happened to have come to Piratesâ Hill. âBecause I hoped Bowden was here and I wanted to have him arrested for selling fake stock certificates.â Mr. Hardy smiled broadly. âYouâve helped me solve my own case of bringing a notorious gang of swindlers to justice. Iâve been tracking this fellowâs friends all over the South. Theyâve been counterfeiting stock, getting prospective customers through the mail and selling them phony certificates.â

Joe inquired when Mr. Hardy had arrived from Florida. âOnly an hour ago,â the detective said. âWhen your telegram came, I flew up. Chet clinched matters by leaving the stock certificate that had blown out of Bowdenâs car. The instant your mother handed it to me I recognized it as a counterfeit.â

Hearing this, the prisoner winced, chagrined to think that he had given himself away by carelessly losing the document.

Collig started to walk toward the shore road. âWeâd better get this man behind bars.â

The others followed. When they reached the police car, the chief phoned headquarters to report he had a prisoner. In turn the sergeant on duty reported that he was holding a suspect for the Hardy boys to identify.

âFollow me in your car,â Collig directed.

On their arrival at police headquarters, Frank and Joe were first shown a black skin-diving suit and a yellow-trimmed skull cap.

âThe spearman that shot at us wore gear like this!â Joe cried out. âSergeant, where did you get it?â

âFrom that man over thereâGuinness.â

The Hardys turned to look. âThe guy who shot rockets at us Fourth of July!â Frank exclaimed. âSay, Guinness, how did you know we were going to be there that night?â

Collig informed both prisoners that they did not have to answer any questions, and advised them of their constitutional rights. But Guinness decided to talk.

âI didnât,â he said, âbut my chance came right then and I took it.â

Guinness admitted he was in league with Latsky, whom he had met recently. But the prisoner denied knowing Bowden or anyone named Gorman.

âWhat about the paper with the name Smedick on it which the police found in your wastebasket?â Frank asked. âDidnât you know Smedick was Gorman?â

Guinness said No, but thought Latsky must have discovered Gormanâs alias and dropped the paper on one of his visits to Guinnessâs room.

âWhere is Gorman?â Frank shot at Bowden.

The man did not answer, but this fact gave Frank a lead. As events flashed through his mind, an idea came to him.

âYou had Gorman attacked at the rear of the beach shack and taken away. Later, you hid him in the trunk compartment of your car. We heard him moan!â

Bowdenâs face went ashen. Frankâs surmise had turned the tide. Bowden confessed that he had lied to the boys about Gormanâs character. He had had him trailed and ambushed at the shack by henchmen. When the Hardys arrived unexpectedly, it had been necessary for the thugs to attack them, too. Worried, they had taken the young detectives to the gully and dumped them. Then they had abandoned the car.

Upon their return to the shack the henchmen had met Bowden and told the story. Later, Bowden had driven past the gully to check and received a real surprise.

âI had to rescue you because I wanted you to think it was on the level,â Bowden said. âThat moan you heard in my car was Gorman. I told you it had been made by the wind.â

âWhere is Gorman now?â Frank demanded.

âYouâll find him in the room next to mine at the motel, tied up. Heâs supposed to be sick and has an attendant. No one else goes in,â Bowden said.

Chief Collig sent two men immediately to release Gorman. While the others waited, more facts were revealed about the case.

During a prison term at the Delmore penitentiary, Bowden, whose real name was Bell, had met Latsky who knew a great deal about ancient cannon, including the story of the Battle of Bayport. Each man was determined to find the treasure for himself after being released. It became a bitter race, with Gorman against both of them.

âFirst you had to locate the cutlass with the directions,â said Frank.

âYes,â Bowden admitted. âLatsky tried to steal the swords from the Bayport Historical Society but failed. Then I took them.â

âI see. And when you found none of them contained the parchment, you had Gil Fanning sell them. Latsky later bought the five cutlasses but could not locate the clue either.â

âAnd you had Chet lured off to be questioned and slugged him. Then you put him in the gully with Frank and me,â Joe said.

As he was talking, two officers walked in with Gorman and an eighteen-year-old youth.

Chet gazed in amazement. âThatâs the fellow who led me into a trap!â he exclaimed.

The new prisoner was identified as Gil Fanning, who had been Gormanâs attendant at the motel. He had needed money, so he agreed to work for Bowden.

âIâI didnât think I was doing anything wrong,â Gil said. âThen first thing I knew, I was in so deep I couldnât get out.â

Bowden admitted that the boy had been his dupe, and hoped that harsh punishment would not be meted out to him. The ex-convict then revealed the names of his henchmen, and Chief Collig ordered their immediate arrest.

The Hardys turned to Gorman and asked if he felt all right. âYes,â he replied, âand Iâm glad you boys uncovered the secret in the cutlass, instead of Latsky and Bowden.â

He told them that the directions to the cannon, according to the legend, had been hidden in the cutlass belonging to the piratesâ captain. Along with five other swords it had been given to someone in the Bayport area for safekeeping.

Gorman had learned about the treasure and the demiculverin from an ancient diary. âIt was written by the wife of the merchantmanâs captain. She tried for years to locate the site of her husbandâs sunken ship.â

Gorman said he was a direct descendant of the captain and that the diary was his property. After his discharge from the Navy he decided to look for the treasure site.

âWhich I never would have discovered if you boys hadnât found the cannon, and Mr. Hardy and the chief hadnât caught Bowden,â Gorman said.

âIt was probably Latsky,â Joe said, âwho threatened Bowden in the message we found on his door and who subsequently sent us a threat.â

Bowden confirmed this. âHe later knocked me out when I was talking to you fellows on the phone.â

âWho was hiding under the tarpaulin in the boat when Halpen warned us away from the sting ray?â Frank asked.

âI was,â Guinness replied. âLatsky had hired me to dive for the sunken treasure ship. When you showed up one morning, I thought you were hunting, too. So I shot a couple of spears at you to scare you off.â

Joe whistled. âWhen I saw that first spear coming, I had no idea that Frank and I would be involved in an undersea treasure hunt!â

When the questioning ended, the prisoners were led away and the others left. Mr. Hardy invited Gorman to stay at their home until he had recovered completely.

âAnd please forgive Joe and me for suspecting you,â Frank said.

âI will on one condition,â Gorman replied with a grin. âThat you show me where that treasure is and let me share with you whatever the government will let us have.â

The Hardys laughed and Joe said, âThat wonât be hard to take!â

âBut first,â said Frank, âfrom whatever we get, I suggest that we buy Tony a new and even better Napoli.â

The others quickly agreed, then Joe said, âI guess this treasure hunt will be the most exciting adventure weâve ever had.â

But another was soon to come their way, which was to become known as The Ghost at Skeleton Rock.

Two days later the whole group, in skin-diving outfits, climbed over the side of the Sleuth and descended to a depth of thirty feet at the same spot they had been fired on by Bowden. There lay the ancient merchantman, its timbers rotted away, and moss and barnacles covering the metal parts.

Cautiously Gorman and the boys swam in and out, removing the debris. At last their search was rewarded. There, in the uncovered hold of the old vessel, lay a vast quantity of gold bullion. Through their masks, the divers beamed at one another triumphantly.

The Hardys and their friends had found the ancient treasure!