Deputy marshal Larry Durant is sent to the town of Spencerville to investigate a vigilante committee operating there. Posing as a gunsmith, Larry rides into town, where he hires Ike, a dispossessed rancher, to be his assistant. Ike, who has lost his ranch in a fire set by the vigilantes, tells Larry that John Spencer, the head of the committee, is an honest man, but Spencer's brother- in-law, Lou Harmon, is the mastermind behind the renegade branch of the committee. Unknown to the honest members of the vigilantes, Harmon and his renegades are using underhanded tactics to drive the ranchers from their lands, which they then buy cheaply at auction, hoping to sell them to the railroad when it builds its line through town. Soon after Larry sets up his shop, he is visited by Harmon and Spencer, who give him twenty-four hours to leave town. Questioning the legality of the vigilantes, Larry ignores their orders. When Spencer's niece, Helen Spencer, and Ike echo Larry's concerns and representatives from the railroad come to survey the town, Spencer decides that the time has come to disband the committee in favor of an organized law force. Harmon, who has been awaiting the arrival of the railroad to sell his ill-gotten land, persuades Spencer to change his mind. When the vigilantes smash his store and order him out of town again, Larry takes Ike to the neighboring town of East Spencerville to question town leader and storekeeper Rufe Jackson about an alleged feud between the towns of Spencerville and East Spencerville. According to the charter of the vigilante committee, the organization was established to keep the peace between the towns, but Rufe claims the feud is just a subterfuge for the illegal activities of the vigilantes. Back in Spencerville, Larry is visited by Bob Allen, a representative of the railroad who is aware of the marshal's mission. After Allen informs Larry that the railroad plans to bypass Spencerville and build its lines through East Spencerville, one of Harmon's men tricks Ike into revealing the information. When Allen's desk is rifled, Ike and Larry trail the vigilantes to the town of East Spencerville, where they demand that Rufe sign over his store to them. A fight ensues when Rufe and his wife resist, and Ike and Larry come to their rescue. Although all but one of the renegades escape, a search of the prisoner reveals the bills of sale to every property in East Spencerville. After revealing his mission to Rufe, Larry wins the support of the townspeople. Larry then presents his evidence of the gang's illegal activities to Spencer, who calls a meeting to disband the group that afternoon. Before he can reach town, however, Spencer is shot in the back by one of Harmon's men. Larry discovers Spencer's body alongside the trail and brings it into town, where Harmon accuses him of murder. Instructing Ike to wait for the outcome of the meeting, Larry rides to tell Helen of her uncle's death. When Harmon incites an attack on East Spencerville, Ike warns Larry, who then rides to East Spencerville to rally the citizens to defend their town. After a blazing shootout between the townsfolk and the vigilantes, Larry apprehends and jails Harmon. When Harmon's men break him out of jail, Larry follows them back to Spencerville, where Larry shoots Harmon after he pulls a gun on him. With peace restored, Larry leaves town, and Ike, who plans to settle down with a mail order bride, is appointed sheriff. When his bride appears with a flock of children in tow, however, Ike changes his mind and scurries after Larry.