This politically taut and fast-paced prison thriller is the most internationally acclaimed Spanish film of the past year. On his first day on the job, prison officer Juan Olivier (Alberto Ammann) is knocked unconscious in a freak accident and his co-workers carry him to an empty cell. When he awakens, Juan discovers that he has been abandoned in the middle of a riot in a high security cellblock-home to the prison's most dangerous criminals. If they discover he's a guard, he's dead meat. To survive, Juan must pose as a prisoner and conspire with the riot's vicious leader, Malamadre (Luis Tosar, the Limits of Control). As the violence escalates and political fallout mounts, Juan uses all his cunning to stay alive.