While traveling on the Orient Express from Istanbul to Paris, detective Hercule Poirot is approached for protection by a mysterious American millionaire, Samual Ratchett. Samual claims someone is trying to murder him, but due to a lack of information Poirot declines the case... until Rachett turns up dead! With the assistance of Antoinette Marceau, an Orient Express employee, Hercule Poirot must overcome a sprained ankle and put this mystery to rest.