The film opens with a group of kids pretending to play bullfighting. They are a group of street kids in Mexico. El Jaibo escapes from a juvenile jail and comes back to meet the kids, which is his street gang that he leads. He tells them that he's learned a lot and intends to show them how to make money stealing. The spot a blind man singing and they attempt to steal his bag, but he wards them off. El Jaibo then takes two of the boys with him to beat the blind man and destroy his drum.
We learn that El Jaibo believes he was betrayed by Julian, a boy who works for his family and brings his father home from the bar as he gets drunk every night. He is by all means a good kid. Jaibo wears a sling on his arm and Julian tells him he will fight him when he heals. As Julian is walking away Jaibo strikes him with a rock then beats him with a large piece of wood. Pedro has to stop him from continuing. We soon learn that Julian died of his wounds. Jaibo demands that Pedro not tell anyone as he will be an accomplice to murder if he does.
Pedro sets out to be good from here on out and gets a job working as an apprentice for a knife smith. Jaibo comes to visit him and while there steals a silver-handled knife without Pedro seeing. Pedro is then accused of being the one who stole the knife. It is alluded to that Jaibo has some sort of relations with Pedro's mother. She then takes Pedro away to a juvenile rehabilitation program. He proclaims his innocence to his mother who visits him, and she finally believes him. When she returns home Jaibo shows up and she tells him to stop coming around as she knows it was him who set her son up.
Pedro has a hard time with the kids in the program and gets in a fight before killing two chickens with a stick. The director of the program allows Pedro to leave the grounds and gives him 50 pesos to run errands with in order to show Pedro that he trusts him. But Jaibo steals the money from him. Pedro finds Jaibo and fights him when he doesn't give the money back. after Pedro is beaten he proclaims to everyone listening that Jaibo killed Julian. The Blind Man hears this and tells the police.
Pedro goes to look for Jaibo in the night in order to kill him, but Pedro ends up being killed by Jaibo. He walks away after taking Pedro's life and is shot by the cops in the street. Meche and her grandfather take Pedro's body from the shed where he was killed and dump him in a pile of garbage so that they won't be accused by the police. They even pass Pedro's mother searching for him as they head to dispose of his body.
