The Plymouth Express Affair

by Agatha Christie

Hercule Poirot is enlisted by American steel magnate Ebenezer Halliday to investigate the brutal murder of his daughter, Florence Carrington, whose body was discovered stuffed under a seat on the Plymouth Express. The Honorable Mrs. Carrington was traveling to a house party with a fortune in jewels, all of which have vanished. Suspicion initially falls on her estranged, debt-ridden husband and a former lover, the predatory Count de la Rochefour. Poirot, working alongside Inspector Japp, uses his 'little gray cells' to look beyond physical evidence and analyze the psychology of the crime. He realizes the maid’s overly detailed testimony about her mistress's clothing is a calculated plant. The arc follows Poirot as he deconstructs a clever alibi involving a disguise and a staged sighting at a train station. Ultimately, Poirot reveals the maid is actually a notorious criminal accomplice who murdered her mistress for the jewels. The tone is a classic drawing-room mystery, blending high-stakes tragedy with Poirot’s characteristic wit and intellectual superiority.