At the Tiger Club nightclub, singer Sharon Winslow asks private detective Jerry Devery to help her prevent the murder of her husband Fred, one of the club's owners. Sharon is afraid that Fred will be killed by gambler Joe Sapphire, to whom he has amassed a large debt. Sharon also confides that she is in love with her husband's business partner, Stephen Mason, and that she wants to keep her husband alive so that Stephen will not be suspected if Fred is murdered by Sapphire. When Jerry asks Sapphire to call off his hit on Fred, Sapphire tells Jerry that Fred has paid him in full, and that the money was the exact amount reported stolen from the Tiger Club's safe a week earlier. A short time later, Sharon and Stephen find the dead body of her husband, along with a suicide note instructing Sharon to collect Fred's life insurance money. While Sharon unthinkingly touches a gun on Fred's desk, Stephen burns the note so that the suicide clause on Fred's insurance will not invalidate Sharon's claim. Suspicion soon falls on Sapphire, who later accuses Jerry of setting him up. At the coroner's inquest, Inspector Henry Leggett testifies that Fred was shot at close range, and Mr. White, a representative from the insurance company, suggests that Fred killed himself. Rosie Gargan, a cleaning woman at Fred's office, then testifies that she saw a woman enter Fred's office around the time of the murder. The jury rules the death a murder, and Sharon receives a check for $100,000 from the insurance company. Jerry grows increasingly suspicious of Sharon, however, and decides to pressure Stephen into confessing. Jerry's persistence wears on Stephen, until Sharon, who is actually the murderer, realizes that she is in danger of being exposed. Luring Stephen up to Fred's office, Sharon pushes him out of the window and he falls to his death. The police believe that Stephen killed himself out of remorse for murdering Fred, but Jerry is even more convinced of Sharon's guilt, and in order to prove it, begins courting her. Jerry persuades Sharon to accompany him on a trip, but during the train ride, Sharon realizes that Jerry is only seeking evidence to convict her. Aiming a gun at him, Sharon confesses to Jerry that his suspicions about her are correct. Before Sharon can shoot him, however, the police spring out from their hiding places, as Jerry had arranged, and arrest her.