Humphrey Bogart...out of the PEN...into the jaws of DEATH! In the wake of riots at San Quentin Prison, Army trainer Stephen Jameson (Pat O'Brien) is appointed to take over the job of running the notorious prison. While celebrating with a couple of pals the night before he starts his newjob, Stephen meets captivating nightclub singer May Kennedy (Ann Sheridan). As they get acquainted, her kid brother, petty crook Joe (Bogart--Casablanca), bursts into the room followed by the police who arrest him for robbing a bank. Because the robbery is not his first offense, Joe is sentenced to San Quentin, where he quickly falls in with the wrong crowd. When May visits Joe in prison, she discovers that Stephen is responsible for the harsh treatment of her brother and ends their relationship.