Transsiberian.

Summary: One of those legendary train trips that people used to dream about taking, the Transsiberian Express has probably seen better days. An American couple, Roy (Woody Harrelson) and Jessie (Emily Mortimer), decide to return home the long way from their recent sojourn in Peking and meet another couple from the West, Carlos (Eduardo Noriega) and Abby (Kate Mara), with whom they quickly form that tenuous bond that often unites fellow travelers away from home. When Roy gets separated from the train at a stopover, Jessie begins to realize that their compatriots aren't exactly who or what they seem to be. But the real dangers of their unforgettable trip have only begun to surface; Russian cops (Ben Kingsley plays one), mobsters, and locals are still to come.