Upon arriving at the Tokatlian Hotel in Istanbul, private detective Hercule Poirot receives a telegram prompting him to cancel his arrangements and return to London. He instructs the concierge to book a first-class compartment on the Orient Express leaving that night. However this becomes impossible when it is revealed that in an unusual occurrence for the time of year (December), the train is fully booked and Poirot only gets a second-class berth after the intervention of his friend M. Bouc who is a director of the train line Compagnie Internationale des Wagons-Lits and is also boarding the train. After boarding, Poirot is approached by Mr. Samuel Ratchett, a malevolent, elderly American he initially saw at the Tokatlian. Ratchett believes his life is being threatened and attempts to hire Poirot but, due to his distaste, Poirot refuses. I do not like your face, Mr. Ratchett, he says.On the second night of the journey, as he is only travelling to Italy M. Bouc gives up his first class-compartment to Poirot who is going to Calais and on to London (Bouc sleeps in the Pullman Coach which has only one other occupant, a Greek doctor named Constantine). This gives Poirot the compartment next to Mr. Ratchett. The train is stopped by a snowdrift near Vinkovci. Several events disturb Poirot's sleep, including a cry emanating from Ratchett's compartment. The next morning, M. Bouc informs him that Ratchett has been murdered and asks Poirot to investigate, in order to avoid complications and bureaucracy when the Yugoslav police arrive. Poirot accepts.