Arizona Territory is in the grip of outlaw terror and killer outlaws, secretly organized by Hulon Champion, who covers his power ambitions with the guise of a respectable firearms merchant. Hoping to eradicate the lawlessness plaguing the newspaperman Fred Gately prints a letter asking the president to visit the area. But Fred's killed by secret gang leader Champion, who also plans to assassinate the president. Undercover officer Rocky Lane teams with his assistant, Nugget, and Fred's spunky daughter to combat Champion's head gunslinger.
The town of Rio Blanco is the center of a fight over the statehood issue and is a perfect setup for Lon Bryson and Chuck Bowers, who organize a couple of phony protection associations. Opposing them is Henry Waterman, publisher of the Rio Blanco Herald. He and his assistant, Andrew Jackson Weems, send for the help of the Territorial Rangers. One of the dispatched Rangers is Jeff Lanning who, unknown to him, has a brother as a member of the gang under an assumed name of Bob Mitchell. Jeff is so shocked at seeing his brother gun down Waterman that he is unable to act in time to prevent it. Unable to explain the cause of is inaction, he is suspended by the governor. Unable to persuade his brother to quit the gang, Jeff, with the aid of Weems and Waterman's daughter Carol, begins his quest to bring the outlaws to justice.
Dick Tracy investiga o roubo de uma fortuna em casacos de pele, uma possível fraude no seguro e vários assassinatos, todos ligados a um formidável bandido que usa um gancho no lugar da mão direita.
