In 1878, outlaws Jim Dawkins, Lorn Reming and Wahoo Jones rob a stagecoach, but later save teenager Rannie Carter from ruthless tax collector Charley Calico, who has murdered her uncle and stolen his cattle. When orphan Rannie tags along, Wahoo tells her that they are cattle inspectors. To get rid of Rannie, Lorn pays elderly rancher Pop Lint $500 to pretend that he is a family friend and take Rannie in as a boarder. Lorn is then separated from Jim and Wahoo when Calico and his gang chase them. Over the course of the next year, Lorn earns a reputation as a notorious outlaw. In order to save Lorn's life, Jim and Wahoo foil his attempt to rob a stagecoach carrying Texas Rangers, and are reluctantly sworn in as Rangers. Jim and Wahoo are quickly tested, however. after Lorn escapes, apparently due to their negligence. After the Rangers are assigned to protect a large cattle herd being driven to Mexico, Lorn steals a portion of the herd, then allows Jim and Wahoo to capture the herd to regain their standing with the Rangers. From then on, Jim and Wahoo give Lorn advance notice of all cattle drives. Not long after, Rannie, now a young woman, asks the Rangers to protect her and Pop Lint from Calico, who controls the territory. By law, the Rangers can only respond to a request made by the mayor of a town, so Jim and Wahoo convince Lorn to help. Lorn agrees to get rid of Calico, but secretly intends to take over Calico's domain. Lorn first forces the sheriff to file a formal request for help with the Rangers. Jim and Wahoo then head out to arrest Calico, whose ranch is near Pop's, and find that Calico and his gang have burned down Pop's stables, causing Pop to die of a heart attack. Jim kills Calico after he brutally tortures one of the Rangers, and Jim is declared a hero. Now determined to go straight, Jim calls off his arrangement with Lorn, who agrees to stay out of the territory. Lorn starts pursuing Rannie, however, becoming Jim's rival for her affection. Rannie rejects Jim's marriage proposal in favor of the suave Lorn, but soon realizes her mistake when Lorn tries to force himself on her. Thrown out by Rannie and rejected by his friends, Lorn busies himself with making trouble for the Rangers. When Lorn is shot and wounded after falling into a Ranger trap, he escapes to Rannie's house, where Jim removes the bullet. Rannie takes care of Lorn while he convalesces, and becomes as convinced of Lorn's evil nature as she is of Jim's goodness. Jim resigns from the Rangers after a manhunt is mounted to find Lorn, but is then arrested for his prior crimes. Wahoo goes after Lorn alone, but is killed in cold blood. Jim demands to be released so he can avenge Wahoo's death, and after Lorn takes Rannie hostage, having promised to leave Jim unharmed, Jim tracks him down in Laredo and refuses to let him escape. The former friends are forced into a gunfight, but it is Rannie who ultimately kills Lorn and avenges Wahoo's death.