In France, United States State Department employee Donald Free is caught trying to steal French state papers and is deported. Because of the publicity, Donald is released from his government job and has a hard time finding another because jobs are scarce during the Depression. One day, he walks into the Peerless Detective Agency, run by the incompetent and crooked Dan Hogan. Hogan does not have customers and Donald does not have a license, so Donald proposes a partnership. Hogan fails to complete his first assignment and starts a dog stealing racket to bring in money. Then, without Donald's knowledge, Hogan connects with gangster Tony Bandor and business booms. Bandor complains that a society woman, Janet Reynolds, is winning too much at his gambling tables and hires Hogan to find some scandal he can use to prevent her from collecting her winnings. Hogan assigns Donald, without telling him the reason for his request. While keeping an eye on Janet, Donald falls in love with her. They begin seeing each other, but Donald is recognized as a private detective by a friend of Janet, who suggests that he is probably spying on her. After learning the truth about his assignment, Donald immediately quits the detective agency, and warns Hogan to stop harrassing Janet. Janet then informs Bandor that she wants to collect her winnings. To help Bandor, Hogan suggests that they make Janet think she has killed Bandor under suspicious conditions. Hogan then double-crosses Bandor by hiring a drug addict to shoot him after Janet leaves the apartment. She then hires the Peerless Agency to help her, and Donald personally takes her case. He learns the identity of Bandor's actual killer and traces him back to Hogan. Meanwhile, Hogan tries to blackmail Janet. After Donald has Hogan arrested, he is offered his old job again. Finally, Janet proposes to Donald and he accepts.