Just after midnight, a snowdrift stops the luxurious Orient Express in its tracks. The train is surprisingly full for the time of year, but by morning, it is one passenger lighter. An American tycoon lies dead in his compartment, stabbed a dozen times, his door locked from the inside. Isolated and with a killer in their midst, detective Hercule Poirot must identify the murderer from among a dozen of the dead man's enemies before the murderer decides to strike again.