Murder On The “Orient Express”

In 1934, famous Belgian detective Hercule Poirot solves a theft at the Church of the Holy Sepulchre in Jerusalem. The obsessive-compulsive—who seeks balance in life, and considers his case-solving ability to see a lie amid truth to be a curse — wants to rest in Istanbul, but must return to London for another case. His friend Bouc, director of the Simplon-route Orient Express service, arranges a bunk for him aboard the train. The other passengers include: American widow Caroline Hubbard, American businessman Edward Ratchett, with his English manservant Edward Masterman and secretary/translator Hector MacQueen; elderly Russian Princess Natalia Dragomiroff and her German maid Hildegarde Schmidt; Hungarian diplomat Count Rudolf Andrenyi and his wife Elena; physician John Arbuthnot; Mary Debenham, a governess; Pilar Estravados, a Spanish missionary; Cuban-American car salesman Biniamino Marquez; and Gerhard Hardman, an Austrian university professor.

Ratchett offers to hire Poirot as his bodyguard during the three-day journey, having received threatening letters from an unknown party, but Poirot refuses. That night, Poirot hears strange noises coming from Ratchett's compartment, and later sees someone in a red kimono running down the hallway. An avalanche derails the train's engine, stranding the passengers.

The next morning, Poirot discovers Ratchett was murdered during the night after having been stabbed a dozen times. Poirot and Bouc investigate the other passengers as repairs begin. Evidence indicates that Ratchett was murdered by one person, and Mrs. Hubbard claims that a man had been in her compartment in the night. Poirot discovers a partially burned note connecting Ratchett to the kidnapping of Daisy Armstrong, a child who was abducted from her bedroom and held for ransom. Though the family paid the ransom, Daisy was murdered nonetheless. Ratchett's true identity is revealed: he was John Cassetti, Daisy's kidnapper and murderer. The shock of her death caused her mother Sonia to die after giving premature birth to a stillborn baby; her father, Colonel John Armstrong, then committed suicide. The family's nursemaid Susanne was wrongly suspected of complicity, leading to her being arrested and subsequent suicide in police custody, only to be found innocent afterwards.

More evidence is found, including a bloodstained handkerchief, and, in Mrs. Hubbard's compartment, the button of a conductor's uniform. The uniform is later found, as is the red kimono — in Poirot's own suitcase. Hubbard is suddenly stabbed in the back; she survives but cannot identify the culprit. Poirot discovers many of the passengers have direct connections to the Armstrong family and uncovers their hidden pasts. While interviewing Debenham, Poirot is shot in the shoulder by Dr. Arbuthnot, who claims responsibility for the murder, but Bouc stops him from killing Poirot. Poirot realizes that Arbuthnot — a former army sniper — never meant to kill him.

Poirot confronts the suspects outside the train, offering two theories of how Cassetti died. The first is simple but does not meet all of the facts: A murderer disguised as a conductor boarded the train at a previous stop, murdered Cassetti, and fled at the stop as the train left. The second is more complex: with every single suspect connected to the Armstrongs, Susanne, or her trial in some way, they all had a motive against Cassetti:

MacQueen's father was the district attorney for the kidnapping case, who was pressured into prosecuting Susanne and sending her to prison, only for his career to be destroyed when the truth was discovered after her suicide

Masterman, who is terminally ill, was Colonel Armstrong's batman during the war, and later his valet, who also acted as butler to the Armstrong household

Dr. Arbuthnot was Colonel Armstrong's comrade and best friend

Countess Andrenyi (née Goldenberg and real name Helena) was Sonia Armstrong's sister and Daisy's aunt

Count Andrenyi was Sonia's brother-in-law

Princess Dragomiroff was Sonia's godmother, and a friend of her mother

Ms. Debenham was Sonia's secretary and Daisy's governess

Schmidt was the Armstrong family's cook

Marquez was the Armstrong family's chauffeur

Estravados was Daisy's nurse

Hardman, whose real name is Cyrus and is American, was a former policeman in love with Susanne

Pierre Michel, the train's conductor, was Susanne's brother

Hubbard is revealed to be Linda Arden, a former stage actress and aspiring director, as well as Sonia's mother and Daisy's grandmother.

Poirot predicts that they acted together, which Hubbard confirms, admitting that she planned the murder and had recruited everyone else to help her. All the other passengers and Michel took turns stabbing Cassetti. Debenham wore the kimono, and Arbuthnot stabbed Hubbard without endangering her life, to convince Poirot of a lone killer. Poirot challenges the passengers and Michel to shoot him with a confiscated gun since he is the only one who can expose their plot; Bouc can lie, but Poirot, obsessed with truth and balance, cannot. Hubbard grabs the gun and tries to commit suicide, but it is empty; Poirot wanted to see how the suspects would react.

With the train back on track, Poirot concludes that justice is impossible in this case, as Cassetti deserved death; for the first time, Poirot will have to live with a lie and imbalance. He presents the lone killer theory to the Yugoslavian police, allowing the others to leave on the train. As he disembarks, a British Army messenger asks him to investigate a death on the Nile. Poirot accepts the case.