When a confused eyewitness identifies New York City cabbie Brick Tennant (Henry Fonda) as a killer, he is sentenced to death for a murder that he wasn't involved in. Though no one is willing to listen to the innocent prisoner's pleas for freedom, Brick's faithful fiancée, Mary (Maureen O'Sullivan), knows that her lover is innocent -- because she was with him when the crime was committed. As the scheduled execution draws ever nearer, Mary begins to investigate the murder herself.