District Attorney Walter Forbes begins an undercover investigation of the city's racketeers. Forbes's aide, Jerry Clayton, arranges for Walter to be bribed by the racketeers so that he can make contact with their leader, but Forbes' contact, Lt. Lee, is killed before the deal is closed. Ex-convict Homer Stone is quickly convicted of his murder. Walter tells Stone's daughter, Margaret, that he knows Stone is innocent, but he has agreed to the ruse in order to convince the gang that the investigation is over. Publisher J. J. Grant, the head of the racketeers, suspects as much, however, and so Walter sends two policemen to act as racketeers trying to muscle in on Grant's turf. Grant sends his henchmen, Joe, Louie and Pete, to stop the two men, and all five are arrested. In the police line-up, store owners are afraid to identify Grant's men for fear of retaliation. Meanwhile, Governor Bill Allen refuses to sign a stay of execution for Stone. Peggy threatens to take her story to the press unless Walter does something to save her father. Walter then asks her to repeat the scene in front of Howell, Grant's attorney, who has arrived to post bail for the trio of henchmen. Howell relates what Peggy said to Grant, who then has her abducted. Grant, who has been masquerading as the indignant leader of a citizen's reform group, meets with Walter, and inadvertantly reveals knowledge that only the head racketeer would know. On a subsequent visit, Walter plants a bugging device in Grant's telephone. During a conversation, Grant admits his part in Lt. Lee's murder. The confession is broadcast on the radio and hearing it, the gangsters release Peggy and leave town in a hurry. Meanwhile, the police arrest Grant. Peggy is reunited with her father and now has Jerry as her beau.