serial

A serial is a multi-part, "short-subject" film that was usually screened a chapter/episode per week at a film theatre. The predominant style of the serial was melodrama; often, each chapter or episode, continually presented in installments over several weeks, would conclude with an unresolved cliffhanger to ensure that audience would return the following week to discover the resolution; popular until the early 1950s. Contrast with "series" and "sequels."