In 1930, toddler Daisy Armstrong, daughter of British Army Colonel Hamish Armstrong and his American wife Sonia, is kidnapped and murdered. In December 1935,
Hercule Poirot travels from Istanbul to London on the
Orient Express. His old friend, Signor Bianchi, a director of the
company that owns the rail line, arranges Poirot's accommodation after all the first-class compartments are unusually sold out during the off-season. Other passengers include American socialite Harriet Belinda Hubbard; English governess Mary Debenham; Swedish missionary Greta Ohlsson; American businessman Samuel Ratchett, with his secretary/translator Hector McQueen and English valet Edward Beddoes; Italian-American car salesman Antonio "Gino" Foscarelli; elderly Russian Princess Natalia Dragomiroff and her German maid Hildegarde Schmidt; Hungarian Count Rudolf Andrenyi and his wife Elena; British Army Colonel John Arbuthnott; and American theatrical agent Cyrus B. Hardman. The day after the train's departure, Ratchett requests to hire Poirot as a bodyguard as he has received death threats, but Poirot declines despite a very generous fee. When the train stops in
Belgrade, Bianchi gives Poirot his compartment and shares a coach with Greek physician Stavros Constantine. During the night, a snowdrift in
Yugoslavia strands the train, while Poirot is awakened by a moan from Ratchett's compartment. Conductor Pierre Michel is told through the door that it was just a nightmare. Ratchett is dead the next morning; drugged and stabbed twelve times. Poirot finds a charred letter fragment revealing Ratchett's true identity: American gangster Lanfranco Cassetti, who along with an accomplice, had carried out Daisy Armstrong's kidnapping and murder. Cassetti had betrayed his accomplice and fled the country with the ransom money. Mrs. Armstrong then died giving premature birth to a stillborn baby, and Colonel Armstrong committed suicide. A French maidservant Paulette, suspected of complicity in the kidnapping, also committed suicide before being found innocent. Bianchi feels that there is justice in Cassetti's death. Poirot finds Cassetti's broken watch showing 1:15, and concludes that Cassetti was murdered at that time when the moaning was heard. Hubbard says that she found a Wagon-Lit conductor's button in her compartment and a bloodied knife in her makeup bag. Foscarelli says that he knew Cassetti was "Mafioso", and theorizes that he was killed in a Mafia feud. Interviewing Pierre and the passengers individually, Poirot learns McQueen is the son of the
District Attorney from the kidnapping case and knew Mrs. Armstrong; Beddoes was a British Army
batman; Greta Ohlsson has been to America; Countess Andrenyi's maiden name is Grünwald (German for "Greenwood", Mrs. Armstrong's maiden name); Conductor Pierre's daughter died five years earlier of
scarlet fever; Colonel Arbuthnott and Miss Debenham will marry once he has divorced his philandering wife; and Princess Dragomiroff was Sonia's godmother. He also learns that the Armstrong household had a butler, a secretary, a cook, a chauffeur, and a nursemaid. Poirot tricks Schmidt into revealing she had been a cook. Foscarelli denies having been a chauffeur, while Hardman claims to actually be Cassetti's bodyguard. Poirot assembles the suspects and describes two solutions to the murder: the first that Cassetti's murder was a Mafia revenge killing - someone disguised as a Wagon-Lit conductor entered the train at Belgrade and later stabbed Cassetti, discarded the dagger in Hubbard's makeup bag, then escaped when the train was stopped by the snowdrift. Bianchi and Dr. Constantine reject this scenario as absurd, but Poirot says they might reconsider that opinion. The second solution links together all the suspects. In addition to the incriminating revelations Poirot extracted from Hardman, McQueen, Schmidt, and the Princess, Poirot deduces that: • Countess Andrenyi is Mrs. Armstrong's younger sister, Helena • Debenham was the Armstrongs' secretary • Beddoes was the Armstrongs' butler • Ohlsson was Daisy's nursemaid • Arbuthnott was Colonel Armstrong's close friend • Foscerrelli was the Armstrongs’ chauffeur • Pierre was Paulette's father • Hardman was not Cassetti's bodyguard, as Ratchett had tried to hire Poirot for that job. He was actually a former policeman who had fallen in love with Paulette. • Hubbard is revealed to be Linda Arden, mother of Sonia Armstrong and Helena Andrenyi, and the organizer of this "extraordinary revenge". McQueen drugged Cassetti, allowing the conspirators to execute him jointly, each with a stab to the chest totalling 12, the Andrenyis stabbing Cassetti together. They killed Cassetti at 2:00 am while Poirot was asleep. The moan and broken watch were to convince Poirot that the murder occurred at a time when the suspects had alibis. Poirot asks Bianchi to choose one solution before the train is freed from the snowdrift, saying the Yugoslav police would probably prefer the simpler first solution of the Mafia feud. Bianchi chooses the first scenario. Dr. Constantine and Poirot concur, although Poirot struggles with his conscience. The snowdrift is cleared and the train resumes its journey. ==Cast==