The story of two men on different sides of a prison riot: the inmate leading the rebellion and the young guard trapped in the revolt, who poses as a prisoner in a desperate attempt to survive the ordeal.
Juan, a rookie prison guard, shows up at his new workplace a day before his official incorporation. All of the sudden, he suffers an accident minutes before a riot breaks out in the FIES sector, where the most dangerous and feared prisoners are housed. His workmates can only look out for themselves and leave Juan's fainted body locked in Cell 211. When he wakes up, Juan understands the situation and pretends to be one of the prisoners. From that moment on, he has to play it smart without risking his life, not yet knowing what paradoxical trap destiny has prepared for him.