"Happy" MacDonald owns a night club and his wife, "Mrs. Mac," works there as a cashier. She is secretly having an affair with Klauss, the dance director of the club's floor show. Ruth Taylor, the club's lead dancer, becomes friends with a customer, young Michael Rand, who is trying to cope with a tragic past by drinking. His mother had killed his father when she caught him in the apartment of another woman. Touched by Ruth's friendship, Michael decides to marry her.
Later that night, a gangster tries to sell MacDonald illegal alcohol, but he refuses. The bootlegger returns with a gunman and kills MacDonald. "Mrs. Mac," who had been working with the gangster, is also killed. Michael and Ruth accidentally witness her death. Just as the gunman is about to silence them, the police arrive in time to rescue them.