In 1897, in the town of Chalmers, Wyoming, Tully Rice, whose father was infamous killer Mark Rice, is ostracized by the local citizenry. Only Sheriff Jim Peyton is sympathetic to the young man's plight. Stating that Tully "doesn't belong in a decent town," Peyton's deputy Nix is antagonistic to him. One day, when Nora Bowdre, the daughter of outlaw Matt Bowdre, comes to buy supplies at the general store where Tully works, Nix harasses her, and when Tully protests, a fight ensues between the two men. After Peyton stops the fight, Nix insists that Tully be arrested, and although Peyton refuses, he realizes that Tully is no longer welcome in town and decides to send him to live with the sheriff's sister in Cheyenne. Embittered, Tully vows to throw in his lot with the Bowdre gang who live in an enclave known as Black Crater in the hills outside town. Bowdre and the rest of the gang are roaming the countryside when Tully arrives, leaving only their sons and elders behind in the Crater. Tully is welcomed by an elderly outlaw named Grandpa Ringo Jones, but the outlaw's grandson, Jonesy, is hostile to the newcomer and incites him to fight. After Tully bests Jonesy, Jonesy takes him to meet the rest of the young toughs, who are led by San Antone. Later, when Nora warns Tully to leave the enclave, he tells her that his father's notoriety resulted in his being exiled from town to town until the sympathetic Peyton brought him to Chalmers. Nora then asserts that Tully will never be free if he stays in Black Crater and confides her plans to leave with her three younger brothers as soon as her father returns and she can make a "clean break" with him. Soon after, the young outlaws invite Tully to join them in robbing a gambler. San Antone explains that gang member Georgie Briggs, unknown to his father, blind card dealer Felix Briggs, is in league with them to rob gamblers of their winnings. Georgie, who serves as his father's "eyes," assures that the gamblers are dealt winning hands, thus providing a lucrative target for the gang. After a gambler named Red Trapnell wins a game of cards, he rides out of town and is ambushed by the gang. When Red resists turning over his winnings, San Antone is about to pistol-whip him until Tully stops him. Sickened by the violence, Tully asks Nora to leave with him, but she insists on waiting for her father to return. When San Antone, angered by Tully's defiance, summons him to the gang's bunkhouse, Nora gives Tully a gun to defend himself. At the bunkhouse, San Antone challenges Tully to draw. Knox Cutler, one of the members of the gang, intervenes, however, and insists that they disarm before confronting each other. Although Tully wins the ensuing fistfight, thus making him the preemptive leader, he is ambivalent about accepting the position. Later, when Peyton rides to Black Crater looking for Tully, Knox orders the sheriff to leave. Tully countermands Knox, thus asserting command of the group. Peyton then tells Tully about finding a beaten gambler on the road who recounted that one man stopped a gang from killing him. When Tully feigns ignorance, Peyton comments that he hoped Tully "would wake up in time to draw the line," then informs him that the man died. Soon after, Knox proposes a plan to rob the Chalmers bank using Tully's inside knowledge of the town. In need of money, Tully tells Nora he is considering the robbery, and Nora replies that if he rides with the gang, she will not welcome him back. When Peyton is notified that Bowdre and his gang have been killed, Nix suggests wiping out the rest of the group at Black Crater, but Peyton hopes that he can convince them to lead peaceful lives. After breaking out of prison, Knox's older brother, Kid Cutler, rides into Black Crater and informs the others that Bowdre and his men have been killed. Bowdre's death frees Nora to leave, and she makes plans with Tully to ride out the next morning. Meanwhile, Kid urges Knox to proceed with the robbery, prompting the impatient Knox to take Nora's brothers and the gang and ride to Chalmers. When Tully learns that the gang has taken Nora's brothers, he hurries to town. As the gang holds up the teller, Peyton and his deputies spot them inside the bank and, in the ensuing gunfight, San Antone is killed. Just then, Tully rides into town and tells Peyton that three defenseless little boys are inside the bank and that Kid is hiding at Black Crater. Tully asks Peyton to let him reason with the outlaws, and as Tully approaches the bank, Knox trains his gun on him. Rebelling, Jonesy points his gun at Knox and orders him to lower his weapon. Upon entering the bank, Tully admonishes the gang to surrender. Jonesy has died from injuries sustained from the gunfight, and the others are wavering when the defiant Knox slings a saddlebag stuffed with cash over his shoulder and uses the boys as a shield until he reaches his horse. With Tully and the law in pursuit, Knox rides to Black Crater and presents the money to his brother. When Kid refuses to let Knox ride with him, the brothers argue. Just as the posse arrives, two gunshots ring out from the bunkhouse, and when Tully runs in, Knox boasts that he has outdrawn his brother, then falls to the ground, dead. After Nora and Tully embrace, Peyton promises to offer the boys care and shelter. Tully then takes Nora to see her brothers.
