Cliffhanger

A cliffhanger is a standard device of serial fiction. It involves the heightening of dramatic tension at the end of an episode to such a degree that the viewer is made anxious about the fates of the protagonists. This, the producers of the work hope, will inspire viewers to return for the next episode, so that they can see how — or if — the protagonists survived.

Cliffhangers were included at the end of almost every episode of the 1963 version of Doctor Who. Most typically, only episode free of cliffhangers was the last one in a serial, although there were periods where even these episodes had at least mild cliffhangers.

As documentary subject
The quality of various cliffhangers — in terms of their efficacy to make viewers return the next week — was the subject of a short documentary on BBC DVD.