When police officer Martin Dunne kills a man in the slums in self-defense, he adopts his orphan son Frankie, and rears him as his own son. By 1935, Martin's wife has died and he retires from the force, going to work as a guard at a bank. Frankie graduates from business college and works as a bookkeeper at the same bank as his father. After much hard work, Frankie is promoted to teller, and he falls in love with co-worker June Hanson. One day he meets his uncle, Willie Loomis, a con-man whom Martin paid to leave town while Frankie was growing up. Willie reveals that Martin killed Frankie's father. The weight of this news changes Frankie's disposition. That night he comes home late, and is so distracted the next day at work, that when he goes to meet Willie at lunch, he mistakenly picks up an envelope containing an $800 deposit. He does not realize his mistake until Martin and the police find him at the bar. Frankie returns the money and swears his innocence, but is dismissed from his job. When he is unable to find June, who is pleading his case with bank manager Parke Lewis, he feels abandoned and listens to Loomis' advice that no one is trustworthy. Frankie subsequently pulls a bank robbery in which he escapes and hides $100,000 in bonds in a wall in the tenement in which he first lived. He is eventually arrested and incarcerated in the state penitentiary, where he finds a childhood friend and befriends the Professor, who is in charge of the prison library. Martin, who has lost all faith in Frankie, resigns from his post. Frankie finally agrees to see June and Martin during visiting hours, and they reaffirm their love for him, convincing him that he must return the bonds in order to salvage his life. Frankie sees a newsreel in which the destruction of various tenements is documented, including the building where Frankie hid the bonds. When the Professor is paroled, Frankie gives him a letter addressed to June in which he divulges the hiding place and asks her to get the bonds for him. The Professor steals the bonds first, then delivers the letter. In a ploy to retrieve the bonds, the issuing company gets Frankie paroled and has him followed, intending to arrest him when he does recover the bonds. June tells Frankie about the Professor's duplicity. When Frankie discovers the hotel the Professor is staying in, June offers to drive him there and takes a meandering route so that Martin can get there first. Martin shoots the Professor in self-defense, and as the bond company's orders were to arrest the man who has the bonds, Frankie is saved. Frankie now realizes that Martin shot his father in self-defense, just as he did with the Professor and, after forgiving him, is ready to rebuild his life.