Young Alejandro (Jeremías Herskovits) lives with his Jewish-Ukrainian parents Jaime (Brontis Jodorowsky) and Sara (Pamela Flores) in Tocopilla, Chile. Jaime is a communist who worships Stalin and raises his son with great severity. Sara sings rather than talks throughout the film, and believes Alejandro to be the reincarnation of her father because of his long blonde hair. Irritated by his wife's delusional views of their son and angered by Alejandro's behavior, which he views as cowardly and effeminate, Jaime cuts off Alejandro's hair (which is depicted as wig in what appears to be magic realism), demands he repudiate the existence of God, and puts him through tests of self-control and bravery which include withstanding being tickled, slapped, and finally undergoing a dental operation without anesthetic. Satisfied with his son's bravery, Jaime acknowledges that he respects Alejandro and arranges for him to be made the mascot of the Tocopilla fire brigade.Alejandro accompanies the fire brigade to the scene of a fire where one of the firemen becomes trapped in the house and burns to death. During the subsequent funeral procession, Alejandro imagines himself lying in the casket with the fireman's corpse, and collapses from fright. Jaime takes him home, but burns the mascot's uniform in front of Alejandro when he wakes up, again calling his son a coward and claiming he is ashamed of him. In an attempt to prove his own bravery to the other firefighters, who he fears look down on him because of his son's cowardice and his Jewish heritage, Jaime attempts to distribute water to plague victims quarantined outside the town, but they kill and eat his donkeys and he himself is infected. He walks back to his shop, visibly infected, and a stand-off with the army ensues. As Jaime goes into convulsions and the army threaten to burn the shop to contain the infection, Sara prays for Jaime's recovery and urinates on him, curing him.Energized by his miraculous recovery, Jaime plans to assassinate the right-wing president Carlos Ibáñez del Campo (Bastian Bodenhofer). He agrees to work with another communist to assassinate Ibáñez at a dog show, but the gun fails and Jaime passes himself off as a hero when he jumps between Ibáñez and the gunman. To get close to Ibáñez, Jaime asks for a job as groom to the president's beloved horse Bucephalus as payment for his heroism. Jaime then poisons Bucephalus as part of his plot to kill Ibáñez, but when Jaime has Ibáñez at gunpoint, his hands become paralyzed.The story returns to Alejandro and Sara, and Sara begins teaching Alejandro how not to be afraid of darkness and how to make sure people don't notice him. She tells him that she knows in her heart that Jaime is alive and loves both of them. They tie a stone to a balloon and release it in the belief it will find its way to him. The rock is then shown falling on the roof of a shack which Jaime is living in. Jaime awakes to discover that he has lost his memory, that he is living with a diminutive peasant woman, and that his arms have been painted the colors of the Chilean flag.Jaime begins a long journey home, but is captured by Nazis and tortured. Rebels free Jaime and return him to his family in Tocopilla. Jaime's hands are healed when Sara tells him "You found in Ibáñez all you admired in Stalin. You are the same as they are! You have lived in the guise of a tyrant." Alejandro, Jaime, and Sara board a ship and leave Tocopilla.