A socialite can't choose between the tough guy she's turned into a gentleman and the gentleman she's turned into a tough guy.

After her mug boyfriend, Red Branahan, is arrested for beating up two policemen, broke Agnes "Aggie" Appleby is evicted from their New York apartment. Desperate for lodging, Aggie shows at the apartment building where her friend Sibby works as a maid and sneaks into an empty room to sleep. Before she wakes, the room's tenant, timid Adoniram Schlump, returns from an unsuccessful day of job hunting. Although Schlump is startled to find Aggie in his bed, he offers her dinner and tells her about his well-to-do family in upstate New York and his fiancée Evangeline. After Aggie describes Red as a doctor who has been imprisoned as a social reformer, Schlump insists that she stay with him, rent free. Soon Aggie transforms the soft-spoken Schlump into a tough-talking mug and changes his name to Red Branahan before taking him to interview for a job with a construction crew. Based on Red's reputation as a fighter, Schlump is hired as a gang boss and his new job and image inspire him to romance Aggie with gentlemanly force. A few months later, Schlump proposes to Aggie, unaware that Red has been released from prison and is looking for her. Although Aggie loves Schlump, she refuses to marry him because of her past with Red, and runs from his apartment when Evangeline and Schlump's snobby aunt Katharine arrive unannounced. Schlump eventually tracks Aggie to her old apartment, where she "confesses" that she is already married to Red. After a love-sick Schlump fights with Red in a speakeasy, he reunites with Evangeline, who is ecstatic over her fiancé's newfound masculinity. Red then returns home and accepts Aggie's orders that he marry her, change his name to Adoniram Schlump, and learn some manners.