A chic American jewel thief falls in love with one of her marks, an English lord.

Wealthy Mr. Kennedy shoots his secretary, Channing, during a parlor game, but it turns out the gun was loaded with real bullets. Luckily, criminologist Phillip Montrose is on hand to help the police. When Kennedy quickly ends up dead as well, the police think it's a tidy murder-suicide, but the family lawyer knows of a letter that voiced Kennedy's suspicions about someone who was out to get him. Soon, the cops are on the trail of a ruthless and clever killer who is one step ahead of even Montrose.

Barry Brandon, a criminal lawyer, visits the night club of Denny Larkin, his primary client, with Betty Walker, a spoiled society girl. The police raid the club and Brandon pleads that the whole group is guilty, just to get even with Larkin for a rebuke. On the same night in court, Madge Carter is on trial for disorderly conduct, and Brandon volunteers to defend her, and proves the case against her if a frame-up. Finding that she is penniless, Brandon hires her as his secretary, and falls in love with her. Brandon is appointed district attorney and has ambitions of becoming the state governor. Having dinner at Betty's home, she maneuvers him, while he is drunk, into marrying her. Later, Madge is a witness when Larkin shoots down a fellow gangster. By threatening Brandon's life, he forces her to commit perjury at his trial, and say he fired in self-defense. Brandon, the prosecuting attorney (who has had his marriage to Betty annulled) knows she is lying but doesn't know why.