In the small town of Sundown, Sheriff Ben Dixon tries to break up a protective association run by saloon owner Mark Robert. The association forces storekeepers and dairy farmers to pay dues or be subject to violence, and leaves the victims too frightened to identify the hoodlums in court. One afternoon, Ben's fiery-tempered son Cliff, whom he has not seen in four years, returns to Sundown and gets into a brawl with some of Roberts' men when they attempt to force dairy farmer Dan Willoughby to join the association. Ben is ambivalent about seeing his son, as "wanted for murder" posters for Cliff have just arrived. Cliff explains that Joe Fenwick, the sheriff of nearby Mason City, was working with the crooked gambler Cliff killed in self-defense and has framed Cliff. Ben insists that Cliff should go back and stand trial, however, and puts his son in jail. Later that evening, Ben attends a meeting of the dairy farmers and convinces them that they can break the association's hold over them by selling their milk at Mason City. Ben guarantees an escort, but Roberts learns about the plan by beating farmer Jensen. The next day, Jensen's body is discovered in a ditch, but the farmers carry on with their journey until the gang surrounds them. Two of the men, Pete Chandler and Luke Allen, are recognized by Willoughby as they destroy his wagon, and he swears out a warrant against them after returning to town. Ben arrests the men and puts them into a cell beside Cliff, although he cannot see them. When Roberts learns of Chandler and Allen's arrest, he goes with Bancroft, another of his henchmen, to the jail, where he shoots Ben while freeing his men. Cliff gets out of his cell and is standing over his father's body when Randall, an influential farmer, arrives. Because only Willoughby knew about the arrests of Chandler and Allen, Randall does not believe Cliff's story about other prisoners and a breakout, and arrests him for murdering his father. Cliff is convicted at his trial when Roberts intimidates Willoughby into not testifying. Soon after, however, Willoughby helps Cliff escape and tells him that it was either Roberts, Bancroft, Chandler or Allen who killed Ben. Cliff investigates, and after a series of accidents in which the other three are killed, discovers that only Roberts could have been the murderer. Cliff confronts Roberts at his saloon, and during a fistfight, Roberts falls through a bannister to the main floor below. Just before he dies, Roberts confesses to killing Ben, and Cliff is cleared. Cliff celebrates by dining with Randall and his daughter Virginia, who reveals that Randall forced Fenwick to drop the phony murder charge against Cliff.