After Alejandra leaves him in Zacatecas, John Grady Cole rides northward, wracked by sorrow. When he reaches Encantada, the town where he, Rawlins, and Blevins were imprisoned, he determines that he will not leave Mexico without retrieving his horse from the captain who impounded it when he falsely arrested the Americans. John Grady breaks into the captain's office and holds him at gunpoint. He forces the captain to take him to the house of the charro, the man who paid to have Blevins executed. There, they find Rawlins' horse. John Grady forces the two men to take him out to the ranch where the other horses--his and Blevins'--are being held.
The horses are there, but as John Grady leaves the stable with them he is shot from behind, in the leg; two of the men who work at the ranch figured out what was happening, and lay in wait for him. In tremendous pain, he manages to mount and ride out of the stable-yard, driving the riderless horses in front of him and taking the captain, whose shoulder was painfully dislocated in the confusion, with him as a hostage. He is pursued by six riders, but manages to evade them throughout the day.
That night, John Grady heats a pistol barrel and uses it to cauterize his wound. The captain is exhausted and in agony, but John Grady, despite his own considerable pain, insists on riding onward through the night and the next day. When he finally sleeps, he is woken by a troop of local men, who question him about the horses and take the captain, but leave John Grady unharmed. Alone now, he continues riding northward through the Mexican countryside, feeling utterly alone, reflecting on the terrible cost of pain and suffering the world exacts on beauty. Finally, John Grady crosses the Rio Grande back into Texas. It is Thanksgiving Day, 1950. He senses that his father has died during his absence, and for the first and only time in this novel John Grady begins to cry.
For weeks, John Grady travels across the border country, looking for the true owner of Blevins' horse. Three men swear out a false warrant for the horse, and the matter goes to court. John Grady tells the full story of how the horse came to be in his possession, starting from the first time he met Blevins. The court is speechless. The judge is stunned, and awards the horse to John Grady. That night, John Grady goes to the judge's house and talks with him, confessing that he is tormented by killing the assassin in the Mexican jail, and by almost killing the captain.
Listening to the radio the next Sunday morning, John Grady hears the Jimmy Blevins Gospel Hour. He rides to meet preacher Blevins, thinking that the boy who claimed to be Jimmy Blevins must have known the preacher, and that perhaps the horse truly belongs to the preacher. This proves not to be the case. Next, John Grady goes to visit Rawlins. They talk about John Grady's experiences in Mexico since Rawlins left, and Rawlins confirms that John Grady's father is dead. A distance has opened up between them, and John Grady realizes that he cannot stay in San Angelo.
John Grady watches the funeral of Abuela, Louisa's mother, the last connection with the old way of life at the ranch. Afterward he drifts westward, riding out into the sunset. The novel ends.