On their way from their ranch in Mexico to sell a herd of cattle in San Antonio, Texas, Gil Reardon, Katy, his wife of two years, and foreman Fierro cross the Rio Grande. When Katy asks why they are not selling their cattle in Laredo, Gil relates that, years earlier, he killed a man working for Ben Keefer, who runs Laredo's cattle market with his sons. Although Gil killed the man in a fair fight, Keefer held him responsible for the death. That night, Keefer and sons, Walt and Jordan, attack Katy and Fierro while Gil is away. Gil returns to help, but is shot and left for dead. When he revives, he finds Fierro dead and Katy near death. After Katy dies, Gil rides to Laredo to confront Keefer. When Bob Sutton, one of Keefer’s men draws his gun on him, Gil shoots and kills him. Keefer then accuses Gil of murdering Sutton. The next day, circuit judge Raymond Parker arrives in town to deliver papers appointing Matt Crawford the new U.S. marshal. Parker oversees Gil’s trial, in which he is found guilty and sentenced to the New Mexico Territorial Prison. After serving four months of his sentence, Gil makes plans with two other inmates to escape. During a driving rainstorm they make their break, and although his companions are shot at the prison wall, Gil escapes. Once the storm subsides, Gil finds a Mescalero Indian woman tied to a tree. After Gil frees her, she tells him that her name is Rosita and that she had been kidnapped by Delgados, the son of an enemy tribe. Just then, Delgados returns from hunting and charges at Gil with a knife. In the ensuing fight, Delgados falls on his own knife and dies. Although Rosita warns Gil that Delgados’ father, Coloradas, will follow their trail, Gil insists that she guide him back to Laredo. As Gil and Rosita travel, she tries to discourage him from revenge, but he says he must deal with Keefer if he is going to live with himself. When a brutal sandstorm strikes, Rosita leads them to a cave where they find refuge. As she wipes the sand from his eyes, they look deeply at each other, and he kisses her. She pulls back, saying she only wants to love once in her life, but when he tells her not to be afraid, she passionately kisses him. When Gil and Rosita reach the Texas foothills, he sends her away, but she returns. Their subsequent argument ends in an embrace, which is interrupted when Crawford and his two deputies, informed that Gil had broken out of prison, come to arrest him. Coloradas, accompanied by his braves, then appears and demands that Rosita and Gil be turned over to him in payment for his son’s death. Gil taunts Coloradas, saying he is not a warrior if he will not fight Gil alone. Angered, Coloradas agrees to the Apache "Battle of the Warriors," a fight to the death in which one tomahawk is placed between the two men. During their battle, Gil gets hold of the tomahawk, assuring his victory. When Coloradas calls to his men to supply him with another tomahawk, Gil throws his weapon into Coloradas' face. After the saddened Indians take their dead leader away, Gil, Rosita and the lawmen ride toward Laredo. On the outskirts of town, Crawford, who believes that Gil was framed for Sutton’s murder, allows him to grab his rifle and escape to settle his score with Keefer. When Keefer learns that Gil is coming, he sends Walt to the roof of a building with a rifle, then walks out to meet Gil with Jordan. During the showdown, Gil notices Walt aiming at him and kills him, then shoots Jordan. Gil orders Keefer to draw, but Keefer throws down his gun and asks what his wife would think if he killed a defenseless man. As Gil hesitates, Keefer reaches for Jordan's gun, and Gil shoots him. After Gil surrenders to Crawford, the marshal sends Gil and Rosita to Gil's spread south of the border, where they will be safe. As the bodies of the Keefers are carried off, the lawmen make up a story about how Gil got away.