Berlin Express

Berlin Express is a 1948 American drama film directed by Jacques Tourneur and starring Robert Ryan, Merle Oberon and Paul Lukas.

Dr. Bernhardt tries to become better acquainted with the other passengers, but they all rebuff his overtures because he is a German. When he retires to his compartment, he is killed by a bomb. While the others are questioned at the next stop, Frankfurt, they learn that the dead man was actually one of the doctors bodyguards. Bernhardt had been posing as another passenger, and Lucienne is his secretary.Bernhardts enemies are not foiled for long. He is kidnapped from the busy train station in broad daylight after he greets Walther Reinhold Schnzel, an old, trusted friend. The U.S. Army quickly institutes a search of the city, but when Lucienne begs her fellow travelers to help look for Bernhardt as they know what he looks like, they at first all decline. One by one, however, they change their minds. ........

Source: Wikipedia