Júlio lives in Porto Alegre, Brazil, with his wife, Márcia. They have a teen daughter, Guida, who plays guitar in a punk band. On a trip to the countryside, Guida's friend Anamaria attempts to seduce Júlio. He resists, but, when he later learns that his wife has been unfaithful, his jealousy motivates him to pursue an affair with Anamaria. Then, he finds her dead body, but there's a problem when all of the evidence indicates that he killed her.