Roy (Woody Harrelson) and Jessie (Emily Mortimer) are the perfect American couple traveling from Beijing to Moscow on the legendary Trans-Siberian Express train. The two strike a bond with another couple, Carlos (Eduardo Noriega) and Abby (Kate Mara), who are not exactly as they appear. Unwittingly, Roy and Jessie are caught in a web of drug trafficking and murderous deceit when all four become targets of ex-KGB detective Grinko's (Ben Kingsley) investigation.