Small-town sheriff Pat Halahan, goes to see the sights in San Francisco, where he captures a pretty burglar, Faith O'Day, when she attempts to rob his room. Pat talks to Faith, and she agrees to give up her life of crime. Pat then takes it upon himself to return a brooch Faith has stolen that same evening. He is detected while putting it back in a jewelry case in a woman's boudoir, and detectives follow him back to the hotel. Faith pretends that she is his wife, telling the detectives that they have been together the entire evening. Faith later escapes from Pat, and he follows her to her home, where he meets Quig Mundy, a gangster. In order to ingratiate himself with Mundy, Pat impersonates The Chicago Kid, a gangster, and joins Mundy's gang. Pat tips off the police, but when the real Chicago Kid shows up, Pat is beaten and locked in a cellar. The police free Pat, and he goes to Faith's house, where he saves her from Mundy, who is shot by a mysterious Chinese undercover agent working ...