After coming to the aid of an oldster, Chet Westoe finds himself being tracked by three unknown riders. A confrontation in the town of Desolation Wells leads to a shootout, but faced with the prospect of jail, Westoe breaks free. He heads for a ranch called the Barbed S, his only clue to the mystery; but there he is entangled in a heap of trouble. The tension builds to a shattering climax as the trail leads straight to an all-out clash with the outlaw gang known as the Bronco Boys...