In 1882, sharp-shooting marshal Frame Johnson apprehends notorious outlaw The Durango Kid and brings him back to Tombstone, Arizona for a fair trial. The whole town, including Frame's two younger brothers, Luther and hotheaded Jimmy, heralds the two men's arrival. Although Frame and the law and order he has brought to Tombstone are widely respected, an angry mob quickly forms around the jail to lynch The Kid. Facing them alone, Frame threatens to shoot anyone who enters the jail, even after Jimmy steps to the head of the crowd. Later, Frame tells Jimmy that he is tired of giving people something they do not appreciate, and that they are leaving town. He then visits his girl friend Jeannie at her casino, and after he informs her that he has given up marshaling for a ranch in Cottonwood, she agrees to marry him. The Johnsons leave town with their friend, coroner Denver Cahoon, planning to send for Jeannie as soon as they are settled. When they arrive at the Cottonwood saloon the next evening, their entrance is noted by local rancher Kurt Durling, whose hand Frame shot off in a cattle-rustling raid. Durling, who now runs Cottonwood, vows revenge. Minutes later, Frame protects young Johnny Benton from the intimidation of Durling's son Bart. After Bart backs down, Durling slaps his son across the face for his cowardice. The next morning, Durling forces newspaper editor Martin to run a false editorial stating that Frame is a cold-blooded murderer posing as a lawman. Frame ignores it, but is drawn in when a mob gathers in the streets to lynch Johnny, who has killed Bart in self-defense. After Frame ensures that crooked sheriff Fin Elder will take Johnny to jail in the next town, a group headed by Judge Williams asks Frame to take over as sheriff and clean up the town, but Frame refuses. He and his brothers travel to the ranch but, seeing how much work it needs, return to town. On the way back, they find Johnny's body hanging from a tree. When the Johnsons confront Elder, he lies that he tried to protect Johnny, and calls Frame a coward for not trying to take over as sheriff. In response, Jimmy punches Elder and Lute volunteers to be sheriff. Frame congratulates Lute but leaves for the ranch with Denver and Jimmy. A few days later, Jimmy is on the outskirts of the ranch when he spots a beautiful girl and follows her home. Even after he realizes that she is Durling's daughter Maria, he declares his love for her. Meanwhile, Durling and his oldest son Frank trick Lute to keep him occupied while they rustle cattle. When Lute finally asks Frame for help, his older brother insists that he not return to his old life. That night, at the saloon, Frank and his henchman Jed shoot Lute. Frame and Jimmy rush to town, arriving just in time to hear Lute apologize for his failure before dying. Furious with both the Durlings and Frame, Jimmy drinks heavily and stalks off to kill Frank, but Denver knocks him out with a bottle to keep him from getting hurt. The next day, Frame announces that he is the new sheriff and that it is illegal to carry a gun in Cottonwood. Although everyone at first refuses, Frame arrests a few men and, when people see Judge Williams backing Frame legally, they comply. Back in Tombstone, Jeannie hears that Lute has died and immediately leaves for Cottonwood. There, she informs Frame that she no longer insists that he give up the law. Later that day, Denver, who has locked Jimmy in the jail, agrees to let him out, and Jimmy immediately grabs his gun. He races to Maria, but before they can flee together, Frank comes home, and trapped, Jimmy kills him. He and Maria rush to Frame's to tell him about the murder, and the sheriff forcibly locks Jimmy into the jail cell, promising him a fair trial. That night, however, Durling sends Jed to release Jimmy from jail, and, just as he has predicted, the next morning the townspeople assume that Frame has let his brother escape. Durling gathers a posse to chase Jimmy, but Frame demands to be the one to track his brother down. When Durling pulls out a gun he has hidden in his coat, an unarmed Frame fights back and the two struggle in the street. Suddenly, a stagecoach racing through the town square runs over Durling, after which Frame hops on a horse and takes off after Jimmy. Easily tracing Jimmy's drunken trail, Frame soon finds him in the hills. Jimmy pulls out a gun, but Frame climbs after him, urging him to turn himself in. At the top, Jimmy shoots Frame in the shoulder, but when his brother collapses, races to his side to rescue him. Judge Williams is trying to dissuade the men from going after Jimmy when Frame and Jimmy return together. Sure that no jury will convict a man who has returned of his own will, Jed and his men flee town. As Maria embraces Jimmy, Frame promises Jeannie that now he is truly through with the law.
