Innocent Judy Wingate works hard in a factory to support her dissolute stepmother Frances, who is engaged to gangster Eddie Nolan. One evening after Judy returns from work, Frances and Eddie leave for a night on the town with their friend, Grover Mullins, the right-hand man of gang boss Gorno. At midnight, Eddie returns to the apartment a few minutes before the others. He makes violent advances toward Judy, who panics and hits him over the head with a frying pan. Frances enters as Judy is leaving in hysterics and, filled with rage over Eddie's attempted infidelity, Frances kills him by hitting him again with the pan. Judy is arrested for Eddie's murder, and newspaper editor Linton assigns investigative reporter Dan Donahue to cover her trial. Dan and Judy are quickly smitten with each other when he interviews her, and Dan suspects that Frances knows more about the case than she is revealing. His suspicion is confirmed when he visits her apartment and she contradicts the story she told the police. Dan still lacks hard evidence, however, and Judy is convicted and sentenced to five years in a women's prison. Dan promises to wait for her and care for her beloved dog "Nipper." While upset about being incarcerated, Judy is nonetheless pleased by the prison's pleasant living conditions and tells her cellmate, Eve Abbott, that prison is preferable to life with her stepmother. Meanwhile, Frances is consumed with remorse and worries that Judy will implicate her, so she pleads with Mullins and Gorno to get Judy out of prison. In exchange for Judy's $10,000 life insurance policy, Gorno and his gang sneak Judy out of prison and dynamite a corpse they have left in her bed, thereby making identification of it impossible. Judy, assumed to be dead by the authorities, is then taken to Frances' new apartment. Judy is greatly distressed by her new predicament and escapes to Dan's place, from which she calls Frances to warn her that she is going to the police. Gorno is furious at Frances for putting him in such a dangerous position and orders Mullins to dispose of her while he pursues Judy. He finds her and Dan at the police station as she is about to turn herself in and threatens them to keep quiet. Just then, news arrives that Frances, who threw herself out of Mullins' speeding car, is in the hospital and wishes to make a deathbed confession. Judy and Dan rush to the hospital, where Frances confesses that she delivered the fatal blow to Eddie and helped engineer Judy's prison escape. Gorno shoots Frances as she is about to reveal his name, but he is in turn shot by the police. After Mullins is apprehended, Judy is cleared of all charges, and she and Dan are free to marry.