Though he is not aware of it, newly elected District Attorney Robert A. Thorne bears a very strong resemblance to an ex-convict named Don Carney. The resemblance does not go unnoticed by crime boss Jim Locke, who fears that the new district attorney will make good on his threats to crack down on crime. As part of his plan to prevent Robert from enacting his reforms, Locke abducts the new district attorney and prepares to have him replaced with Carney. Carney spends a week with Robert, learning all the important details about his life and rehearsing himself for his role as the new district attorney. While the press reports Robert's disappearance and the police begin a citywide search, Martha McCormack, Robert's girl friend and a reporter for her father's newspaper, begins her own search for Robert. She begins her investigation with only one lead: an old photograph of a man resembling Robert, which was found by police at the scene of a recent murder. Because the photograph was printed on rare paper that is easily traceable, Martha is able to locate the picture's developer and determine the identity of the man. Though unable to find Carney, Martha locates his wife Jill, who tells her that her husband was paroled and is now living on a ranch. Meanwhile, at Locke's hideout, Carney is overpowered by Robert and knocked unconscious. When Knuckle, one of Locke's gunmen, enters the room, Robert, posing as Carney, tells him that their captive tried to escape. Believing Robert, Knuckle shoots Carney, and then takes Robert to the cliff area where he is to be "discovered" by police lieutenant Wall. Realizing that Wall is in league with Locke, Robert sets out to expose the web of corruption in his city, and does so by suppressing his true identity and playing along with Locke's scheme. Robert manages to fool his old colleagues and Locke's gang until he kisses Jill and she realizes that Robert is not her husband. Jill reports her suspicions to Wall, who tries to flee with Locke's money before the police close in on their operation. When the police arrive to arrest Locke, Locke fires his gun at Wall, who falls to the ground. In his final moment Wall shoots and kills Locke. With the political corruption exposed and eliminated, Robert and Martha resume their romance and seal their love with a kiss.