Frank Taylor (Humphrey Bogart) believes he is about to be made foreman of the factory he works in. When the job goes to a Polish-born worker instead, Frank is enraged and decides to join a local organization that persecutes immigrants. Known as the Black Legion, the clandestine hate group uses scare tactics to help Frank get his promotion. However, his involvement with the Legion has dire effects on his marriage and jeopardizes the life of his best friend, Ed (Dick Foran).