serial

an adventurous and melodramatic incident divided into many chapters of about twenty minutes each. These were the domain of villains and heroes, each chapter ended with a cliffhanger in which the hero was left in some deadly danger from which it was plain he could not escape, but at the beginning of the next chapter he did. [from definition of "Perils of Pauline, The" It was one of the most popular serials of its time.