Longley continues to act as the acting US Marshal in the Texas-Mexico border territory to find out and arrest "The Shadow," who is controlling criminal enterprises in the region. Having prohibited gun within the town limits of Rio Nada, Longley faces opposition from one of the saloon owners who hires two gunfighters to kill Longley. One of them, The Brazos Kid, is a friend of Longley's. The other, celebrated gunfighter Luke Short, agrees to kill Longley.