When Elspeth McGillicuddy witnesses a strangulation on a passing train, she enlists her friend Jane Marple to locate the body and identify the killer. Miss Marple must navigate the complex social dynamics of the Crackenthorpe family estate, where the victim is suspected to be hidden. She relies on the assistance of Lucy Eyelesbarrow, a professional housekeeper, to infiltrate the household and gather evidence. The narrative unfolds through a third-person perspective that emphasizes the observational skills of the elderly detective as she pieces together clues from seemingly mundane interactions.

This novel is widely regarded as a quintessential example of Christie's later work, showcasing her mastery of the traditional whodunit structure. Readers often highlight the cleverness of the central premise and the dynamic between the elderly Miss Marple and the younger, pragmatic Lucy Eyelesbarrow. The setting of the Crackenthorpe estate provides a classic atmosphere that enhances the tension of the unfolding investigation. Critics frequently note that the book maintains a brisk pace while delivering a satisfyingly complex resolution to the mystery. The work remains a staple for fans of Golden Age detective fiction who appreciate intricate puzzles and sharp character observations.