As they drive their cattle through Wyoming, Stony Brooke, Tucson Smith and Rusty Joslin, known as The Three Mesquiteers, take refuge in an abandoned house during a dust storm. After the wind subsides, they notice that one cow from the ranch's herd has been slaughtered and carried off by a man on foot. While Tucson and Rusty search for the rustler, Stony rides into the town of Mesquite where he becomes embroiled in a fight with an underling of Balsinger, the corrupt chairman of the public works program, after the man tries to force a young woman named Irene Parker to meet with Balsinger. After the fight, Stony insists upon accompanying Irene home, where he finds Tucson and Rusty, who have come in search of the rustler, Irene's brother Will. Learning that the Parker family has lived in poverty since Irene and Will's father Luke was fired as foreman from the road gang because he refused to collect graft for Balsinger, the three decide to confront the corrupt Balsinger. At Balsinger's office, a fight ensues between the Mesquiteers and Balsinger's men, and the office is destroyed. To put a halt to Balsinger's reign, Stony decides to go to the state capital to testify, but in his absence, Will is arrested for violating the federal game laws when he shoots a deer in order to feed his hungry family. Stony's testimony results in the scheduling of a public hearing in Mesquite, but when the Mesquiteers are arrested for destroying Balsinger's office, Balsinger's men succeed in intimidating the townfolk to keep them from testifying. Embittered by the outrages perpetrated by the corrupt Balsinger, Will breaks out of jail and turns against society. Dogged by a posse, Will rides into town where he finds Balsinger at the bank. After shooting into the street to attract attention, Will pushes Balsinger outside where they both perish in a hail of bullets.