When battered prize-fighter Lee Burke is taken to the West Side hospital, nurse Katherine MacDonald leaves her romantically-inclined patient, wealthy attorney John Dodge to take care of Burke. She discovers that Burke was doped by his handler, Churchill, on instructions from gambler Joe Largo so the latter can win a $5000 bet from Burke's manager Slice Cavanaugh. Largo orders henchman Larry Carson to bump off Churchill to keep him from talking. Katherine talks Burke into quitting the ring and Dodge belittles the ex-boxer by getting him a job as a bellhop. Cavanaugh, desperate for money, calls Burke yellow and when Burke happens upon the scene where another Largo henchman, Smiley, has killed the manager, Burke is tried for the murder.