Through the window of a passing train, Miss Marple (Margaret Rutherford) spots a woman being murdered. When no corpse can be found, however, her suspicions are dismissed as the ravings of an eccentric elderly spinster. Determined to solve the mystery, she takes a job as a maid at the estate of James Robertson-Justice... The first screen adaptation to star Rutherford as Agatha Christie's amateur sleuth only holds the interest now because of its star's unique persona and comic timing. Thanks to her, this otherwise uninteresting film found popularity and spawned three sequels.

Miss Marple believes she's seen a murder in a passing-by train, yet when the police find no evidence she decides to investigate it on her own.