A veteran policeman named Fernando feels a lot of hatred against Ángel because the boy ran him over with a car leaving him lame. Now Fernando accuses the young crook of having participated in a robbery at a gas station in which a murder has occurred. Helped by his friends, Ángel rebuilds the facts that serve him as an alibi, but while he is in pre-trial detention in La Modelo prison (Barcelona) a terrible mutiny will take place..