cliffhanger

Cliffhanger is a film characterized by scenes of great tension, danger, adventure, suspense, or high drama, often climaxing at the end of a film, or at the end of a multi-part serial episode, where the plot ending and the fate of the protagonist(s) are left unresolved. The name was derived from the movie serials of the 1930s where each week the hero was perilously left dangling from a cliff with a "to-be-continued" ending to increase interest for the next episode (sequel).