A dying man accuses Nolan, a powerful gangster, of his murder. Nolan is already under investigation for allowing gambling in his nightclub. Police detective Mac McCue is working undercover at the club when Bob Larkin, McCue's partner and friendly rival, arrives to arrest Nolan for the killing. At the club, McCue picks up Lil Daley, a pretty woman he knows slightly. Under orders from Diamonds Jareck, Nolan's right-hand man, Lil invites McCue to her apartment where Diamonds' men plan to kill him. Before they arrive, however, McCue leaves. The next day, Larkin, intending to steal Lil from McCue, contrives to meet her. It is love at first sight for both Lil and Larkin. Upon discovering the trick, McCue disables Larkin's car, making him late for roll call. The two men fight, and in the confusion, a prisoner McCue was escorting escapes. McCue and Larkin are dismissed from the detective bureau, but because of their earlier good records, they are allowed to remain on the force as members of the riot squad. Meanwhile, Nolan is brought to trial and convicted. Larkin discovers that there is another man in Lil's life, whom she will not name, and insists that she break off with him. Fearful for her life, Lil refuses, and Larkin leaves her. When Peggy Moore, the daughter of Judge Moore, who is to sentence Nolan, disappears, McCue questions Lil. Her maid, Ruth, overhears their conversation and sends for Diamonds, who kidnaps McCue. When Larkin learns that McCue is missing, he forces Lil to name his captor. Despite his concern for his daughter, Moore sentences Nolan to death. Diamonds now knows that he must kill McCue and Peggy, but just in time, Larkin arrives with the riot squad and frees them. Lil and Larkin are now free to marry, and in Peggy, McCue has found his ideal woman.