Santiago, a jolly modern bandito, has just lost his partner when he happens on the isolated farm of young Manuel and Maria Lopez. Manuel's aid is enlisted in what develops into a violent encounter with Santiago's fence. Exposed to money, the fast life, and Santiago's anarchistic philosophy, Manuel (formerly simple and hardworking) is in serious danger of being corrupted (and Maria is not immune either)...

In Mexico, two bandits, Santiago and Vicente, rob a stopped train of its cargo of boxed watches. When a guard shoots Vicente, Santiago shoots him and helps Vicente escape. In the hills, Santiago comforts the dying Vicente by recounting their tale, in which the two friends are forced into a life a crime because of Mexico's frequently changing political alliances, which led them to be imprisoned, even though they were innocent of any wrongdoing. Santiago assures Vicente that in heaven, San Pedro will realize that their jail escape and thefts were performed out of necessity, and will give them their due. After Vicente dies, Santiago buries him and travels on alone. One day he spots a lovely woman, Maria Lopez, gathering water at a stream, and follows her home. Santiago meets her husband Manuelo, a poor young farmer struggling to settle his land. At dinner, Maria reveals to Santiago, to whom she feels drawn, that she was a servant who was sold to Manuelo along with the land. Later that night, Santiago offers Manuelo cash to drive him to a nearby town. They stop at a U.S. Customs office, where Santiago delivers the stolen watches to the shipping agent, Gunts. He asks Gunts why he failed to meet him and Vicente at the train as promised, but Gunts dismisses his concerns. Upon discovering that Vicente has died, Gunts insists that he will pay only half the fee, after which Santiago calmly forces him at gunpoint to put a noose around his neck and step up on a chair. As Manuelo cowers in fear, Santiago kicks the chair out from under Gunts long enough to terrify him into giving them the combination to the safe. His pockets now loaded with money, Santiago takes Manuelo to a local dance hall, where they drink, dance and fight. At home, where they are all to sleep in one room, Manuelo informs Santiago that if the money was his, he would use it to build his farm rather than wasting it on liquor and women. Angry, Santiago throws some of the bills on the floor and stalks outside to sleep in the barn. When Maria berates Manuelo for insulting their guest, Manuelo beats her and then devises a plan to kill the drifter and steal his money. Trembling, he sneaks out to the barn, but Santiago, hearing a noise, lays in wait. Upon seeing Manuelo, Santiago assumes the young man has come out to apologize, and his kindness strips Manuelo of his drunken courage. The next morning, when Santiago comes inside for breakfast, Maria asks him to tell her about the places he has visited. When he paints glowing pictures of Vera Cruz, she throws herself at his feet and begs him to take her with him, but he then admits that the reality of his life is bleak and lonely. She cries that even being hungry and cold would be better than her current life, but Santiago harshly informs her that he would grow tired of her. Shaken, he prepares to leave the farm, but first stops to say goodbye to Manuelo. The younger man is waiting in the well pit with his gun drawn, but just as Santiago approaches, a rattlesnake climbs into the pit. Santiago shoots it, saving Manuelo, who falls to his knees, begging forgiveness for thinking about killing him. Furious, Santiago almost shoots Manuelo when Maria races out and pleads with him to spare her husband, if only to keep himself out of jail so they can run away together. Santiago agrees, and although Manuelo promises Maria everything will change if she stays, she leaves with Santiago. Immediately, however, they hear a car approach the farm and ride back in time to witness Gunts and two policemen preparing to hang Manuelo for the safe robbery. Santiago shoots Gunts and the police run away. He then instructs Manuelo to join Maria on her horse and tells them he will meet them down the road. Just as they leave, however, Gunts stirs and shoots Santiago in the back. Santiago kills Gunts but, realizing he is mortally wounded, joins Manuelo and Maria long enough to urge them to reconcile and ride ahead of him. As soon as they ride off together, he collapses, repeating to himself that in heaven, San Pedro will award him the peaceful life that he deserves.