Benoit, the head guard of Clouville Prison, prefers to be liked than feared. This basic principle transforms the jail-house into a joyful prison, where all the inmates live amicably together. Among them, various colorful characters : a farmer, a poacher, a distiller, a forger, two pickpockets, a safe-cracker, a gangster and... a good-looking guy who pleases Rosette, Benoit's daughter, well. But too much leniency takes its toll : after Vauclin, the gangster, manages to escape and a complaint is filed against "the deplorable disorder reigning in the joyful prison", Benoit is given early retirement. He will know how to take advantage of his new status live a joyful life with his wife, his daughter and André, his son in law, in fact the nice-looking young prisoner who, in the meantime, has been cleared of all charges.