A society lawyer defending gangsters turns detective to prove his girl-friend's fiancé was framed for a murder.
After getting gangster Tony Gazzati (Nat Pendleton) acquitted of murder, lawyer Jackson Durant (Warner Baxter) refuses $50,000. His firm lets him go because he wants to continue defending underworld types. Durant dismisses two bodyguards, but they keep following him. He finds Sue Leonard (Martha Sleeper) and kisses her, but she complains about his representing criminals. She and Tom Siddall (Phillips Holmes) decide to marry. Siddall calls on Mimi Montagne (Mae Clarke) and offers her a settlement. Angry, she calls Jim Crelliman (C. Henry Gordon) and goes to see him. He wants her to tell Siddall it is over. They go out on the balcony, and she is shot dead. Siddall is arrested for murder.
Durant's butler Layton (Charles Butterworth) tells him what he did while drunk. Sue tells Durant she is engaged to Siddall and asks him to defend him. Durant does not forgive her, and a phone call warns him not to help Siddall. Although circumstantial evidence is overwhelming, Siddall protests he did not kill Mimi; Durant believes him. Durant finds out from Gazzati that Crelliman and his men have alibis. Gazzati has told Durant he can have any woman he wants and introduces him to Gertie Waxted (Myrna Loy). He takes her home and protects her as Mimi's friend, questioning her. She stays all night while he sleeps on his couch. The police bring Durant a photo, and Sue asks him to get off the case because his life is threatened. Gertie tells Sue that Durant is in love with her (Sue). Durant tells Gertie not to leave his apartment and takes her watch to the pawnbroker who claimed he sold Siddall the gun. The pawnbroker refuses to help Durant but is soon murdered. Durant gets keys from Gazzati and goes to Crelliman's apartment building, where Gertie lives next to the balcony of the murder. Crelliman offers him a trip to Europe and threatens him; but Durant slugs him. Crelliman's men are looking for Durant to kill him, but the elevator man helps him escape. Durant suspects Murtock in the room above and sees Gertie with him at a speakeasy. She tells Durant she drew Murtock there so he wouldn't kill Durant. The police find Murtock in his room, and Durant tells him he is going to kill Crelliman and frame Murtock. Gertie gets Crelliman to go on the balcony, and Murtock confesses Crelliman hired him to kill Mimi. Gazzati kills Crelliman and is killed. Durant plans to marry Gertie and take her to Europe.
This gangster mystery combines intrigue with wit and romance. Friendship with Gazzati and Gertie enables Durant to solve the case.