Hoot Gibson and Bob Stanley ride into Arizona seeking the killer of Bob’s father, who managed the stagecoach line in Eggleston for Kelso McGuire. They intercept a stagecoach holdup, and meet Sally and Tom Buchanan, who are going to Eggleston to purchase a ranch. They come across a murdered rancher who has quarreled with Corey, owner of the water company in Eggleston. Suspicion for the killing of Bob’s father falls on Randall, who now runs the stagecoach line. Hoot and Bob help the Buchanans set up their new ranch, and other ranchers ask Bob to form a Vigilante group, to rid the territory of land-jumpers. McGuire, secretly the gang leader behind all of the trouble who wants to gain control of Arizona, tries to incite a lynch mob to hang Randall for the killing of the rancher. Hoot and Bob save Randall from the mob, and Randall produces a letter to him from Bob’s father, asking him to come to Eggleston to help clean up the land-grabbers. Forcing McGuire into his own ambush which had been set up for Hoot and Bob, the pair get a confession from McGuire that he killed Bob’s father, and also had one of his henchmen murder the rancher.