Miss Marple's bloodhound instincts are triggered when a friend thinks she sees a murder on a train. When police cannot find a body and cast doubt on the story, Miss Marple decides to investigate. She thinks the body could be found on the banks belonging to Crackenthorpe house, a stately mansion and enlists professional housekeeper Lucy Eyelesbarrow to go undercover. The body of the woman is eventually discovered in a barn. Mystery, starring Joan Hickson