The praises of a prison, the famous Sing Sing, are sung in this picture authored by Sing Sing's long-term reform warden, Lewis E. Lawes. Cocksure criminal Spencer Tracy is sent to the slammer on a felony rap. There he is greeted by the kindly warden, A.S. Byron, who explains that good behavior brings certain privileges. Tough-guy Tracy starts a near-riot and gets 90 days in solitary, where he resolves to escape. He joins some prisoners who are planning an escape attempt until he discovers that their plan is set for Tuesday (he has an odd superstition relating to the days of the week). Beaten at last, he determines to win parole through good behavior. Meanwhile, Tracy's girlfriend Davis--attempting to win his parole by other means--seeks the assistance of powerful mob chief Harold Huber. In return for his help, Huber wants Davis's favors. While speeding down a street in a car, Davis repels the gangster's groping and is seriously injured in the resulting automobile crash. When warden Byron hears of her condition, he offers Tracy--now a trustee--compassionate leave to visit Davis. On the outside, however, Tracy runs into some detectives who mistake him for an escapee. A disastrous shootout follows. (Verleiher-Text)