A hapless small-time Roman crook, Cosimo (Memmo Carotenuto), is arrested for a bungled car theft and sentenced to a few months in prison. He harangues his girlfriend and lawyer to get him released, and even tries to get one of his friends to confess to his crime, so he may carry out a heist idea stolen from another inmate, a dishonest bricklayer who purposely constructed a flimsy wall between a pawn shop safe and an adjacent vacant apartment. Ultimately, his gang bribes an acquaintance with a clean criminal record, a boxer named Peppe (Vittorio Gassman) to confess. The warden does not believe Peppe, however, and he ends up in jail alongside Cosimo. Peppe tells Cosimo that he has been sentenced to three long years for this minor offense and Cosimo, to justify his actions, explains the details of the pawn shop heist to Peppe. Peppe then gleefully reveals that he has been given a year's probation and walks out the prison gate, infuriating Cosimo.