Chato makes several large bets on Conquistador and places a row of spikes on the wall jump to scare the horse into jumping high enough to clear it. When Conquistador swerves away from the jump after the spikes injure him, Chato mercilessly beats the horse. As Pablito tries to intercede, Chato takes the whip to his stepson as well. That night, Chato threatens to hurt Conquistador if Pablito tells the general about the trainer's cruel treatment or his bets. Days later at the competition, after Conquistador fails to clear the wall jump, Torres and his daughter ask Pablito why Conquistador is frightened, but Pablito, recalling his step-father’s threats, does not divulge Chato's secret. One day at the ranch while her father is away, Celita tries to coax Conquistador to jump the wall, but the horse balks, injuring his leg and throwing Celita from the saddle. Arriving home just in time to see the accident, Torres orders Chato to fire Pablito and destroy Conquistador. While Chato returns to the stables to load his gun, Pablito flees the ranch with Conquistador.
When Chato comes to the barber shop, he is confronted by his creditors who demand that he pay his gambling debts, prompting him to flee. Pablito and Conquistador wander across the countryside for two days and nights until they reach a deserted town, where two bandits, Vulture and Tiger, try to hitch Conquistador to their wagon. When Pablito tells them about the wound, Tiger generously gives the horse a medicinal cure and suggests Pablito escape the area by train, sending him to railway man Garcia to ask for free passage. Upon learning that Conquistador is Torres' horse, Garcia secretly arranges to meet Torres' men down the line in San Juan to trade the horse for a reward, but when they reach San Juan, the officers fail to deliver the money and the horse is spared. Pablito and Conquistador get off the train at San Miguel de Allende, where they take refuge in a doorway during the rainy night. In the morning, Pablito and Conquistador join a procession for Saint Anthony, the patron saint of animals, along with villagers shepherding a wide variety of pets and farm animals. As they make their way through the crowded market place, Chato sees them. Desperate for cover, Pablito leads Conquistador into a church where the Padre, after hearing their story, agrees to harbor the fugitives. When Chato arrives at the church, the Padre tells him that the "sacred law of sanctuary" prevents Chato from removing the horse. The Padre then makes breakfast for the boy and warns him that living as a fugitive will turn him into an outlaw. The next day, the Padre takes Pablito and Conquistador, ill from his wounds, to a large cattle ranch where the owner and matador Don Pepe Ortiz introduces them to the veterinarian Ignacio. While Ignacio cares for the horse, Pepe offers to talk to Torres, an honorary judge at the bullfight scheduled in San Miguel the next day, to plead for Conquistador. He then suggests Pablito gather his courage and talk to Torres himself, but the boy refuses. Suddenly a bull breaks free from his corral and chases Conquistador into the fields. Don Pepe and several men go after the horse but return late that evening empty-handed.
The next morning, on the drive back to San Miguel, the Padre and Pablito meet a caravan of gypsies. After Pablito spots Conquistador's bridle on one of their donkeys, one of the gypsies admits that he has sold the horse to a man involved in the bullfight in San Miquel. Meanwhile, at the bull ring plaza, Conquistador is being saddled up for the ring. After the Padre's old car "Doroteo" breaks down just inside the town, he and the boy run the last few blocks. Chato sees the pair on the street and follows them to the arena, where a picador enters the ring riding Conquistador but is soon thrown from the horse, leaving Conquistador alone in the ring with the angry bull. Fearing for Conquistador's life, Pablito jumps into the ring and onto Conquistador's back. When the bull immediately charges, Pablito races the horse over the steep gates of the ring. Meanwhile, Chato's creditors spot him in the arena and carry him away kicking and screaming. Torres, who is attending the bullfight, decides to spare Conquistador. When he returns home to tell the boy's heroic tale to his daughter, Pablito and Conquistador arrive at the ranch. After Pablito asks Torres to punish him not the horse, Torres forgives the boy by telling him Conquistador is now his. Days later, after Celita is fully recovered, she and Pablito ride through the Mexican countryside, easily clearing every jump in their path.