 Rufino (15) roams the streets of Mexico City. He tries his best to look after the youngest homeless children who survive on a diet of glue and hash and sleep in the sewers at night. Rufino earns some money doing hard and dirty work, such as moving meat around a slaughterhouse. Rufino sells a bag of cocaine for Ochoa, a corrupt cop who has Rufino s district in his power and is also the lover of Rufino s adoptive mother. He decides to use the money to flee the city with his girlfriend and her baby. Ochoa sets off after them. Just as Rufino seems able to escape, he finds out that his real father is still alive. Obsessed by this knowledge, Rufino doesn t want to leave until he has found his father.