Marathon Man (1976)

Thomas "Babe" Levy (Dustin Hoffman) is a Columbia graduate student and long-distance runner who is oblivious to the fact that his older brother, Doc (Roy Scheider), is a government agent chasing down a Nazi war criminal (Laurence Olivier) -- that is, until Doc is murdered and Babe finds himself knee-deep in a tangle of stolen gems and sadistic madmen. Even his girlfriend, Elsa (Marthe Keller), becomes a suspect as everything Babe believed to be true is suddenly turned upside down.