When Charley Enley Kyng, the owner of an underground casino, is diagnosed with heart disease, his doctor advises him to give up his profession and slow his pace. Though he has devoted twenty years to his career and has made an honest living at it, Charley knows that it is time to quit and spend time with his loving wife Lon and their teenage son Paul. The Kyngs share their large home with Lon's sister, Alice Elcott, and Alice's dissolute husband Robbin, who works for Charley as a card dealer. Robbin is broke and cannot afford to pay his gambling debts, so when two thugs, Lew "Angie" Debretti and Frank Sistina, try to collect $2,000 from him, he feels he has no alternative but to cheat at Charley's casino. Meanwhile, Paul tells his mother that he is ashamed of his father's business and that he has had to find a new prom date because the last one spurned him when she found out that he is a member of the notorious Kyng family. Charley eventually takes his doctor's advice, and, after giving up drinking, smoking and his life at the casino, decides to go on a fishing trip in the mountains. Before leaving, the Kyngs are visited by an angry couple, Mr. and Mrs. Lorgan, who have lost their life's savings at Charley's casino. After Lon refuses to return their money, the Lorgans threaten to call the police. Lon firmly demands that the couple leave the house, but the incident leaves her in tears. When Paul then rejects his invitation to go fishing, Charley becomes depressed and goes to his casino office, where Ada, an admirer of his, tries to persuade him to have an affair with her. Charley, however, remains committed to saving his family, and refuses Ada's advances. Later that night, at Paul's prom, a fistfight breaks out when Paul refuses to take two fraternity boys to his father's casino. Paul and dozens of his schoolmates are jailed for rioting, but when Charley wins his son's release, he is told that Paul does not wish to see him. Paul is released into his mother's custody, and she tries to reconcile her son and husband by taking Paul to the casino. They arrive just as gambler Jim Kurstyn, who is on a winning streak, is about to bankrupt the casino. Instead of closing the game, Charley allows Jim to raise his bet limit and make larger wagers. Tension mounts as Charley and Jim square off at the craps table, and Charley wins.  Then, Debretti and Sistina burst into the room and hold up the casino. Paul helps his father overpower the gunmen, after which father and son reconcile. Charley goes to his staff and offers to cut cards for ownership of the casino. The staff is shocked and refuse, but one urges Paul to pick their card.  He does and Charley loses the club. Outside, Charley walks away with Lon and Paul. Lon pulls out Charley’s card, which he did not show to the staff and was actually the winning card.