Charlie is an Italian-American man who is trying to move up in the local mafia and who is hampered by his feeling of responsibility towards his childish and destructive friend Johnny Boy. Charlie works for his uncle Giovanni, mostly collecting debts. He is also having a hidden affair with Johnny Boy's cousin, Teresa, who has epilepsy and is ostracized because of her condition - especially by Charlie's uncle.
Charlie is torn between his devout Catholicism and his Mafia ambitions. As the film progresses, Johnny becomes increasingly self-destructive, growing continually more disrespectful of his creditors. Failing to receive redemption in the church, Charlie seeks it through sacrificing himself on Johnny's behalf.