Description France, 1700. After being raped by her own father, young Susanna Simonin is put into a convent to avoid a scandal. The monastery is a weird place however, since the nuns are constantly horny and spend most of their time masturbating and flogging themselves. The Mother Superior is sexually attracted to Susanna, which makes her lover Sister Theresa insanely jealous.
When the Mother Superior contracts tuberculosis, the vile Theresa takes command of the monastery temporarily and misuses her power to make Susanna's life a living hell. Theresa spreads a rumor that Susanna is possessed by the Devil, and locks her in a rat-infested dungeon, then tricks the poor girl into drinking a substance that makes her feverish. She later orders some of the nuns to drag Susanna naked from her bed and she whips her violently, claiming she is just trying to beat the Devil out of her.
The Monsignor hears word that one of the local nuns is demonically possessed and decides to investigate. He sends his personal exorcist to the convent, and Susanna is tied up and tortured and confined to a cell. The exorcist even subjects Susanna to a "holy water douche" to clean the Devil from her body. When the Mother Superior dies, Susanna is accused of causing the woman's death with witchcraft. Finally a trial is held in which Susanna is accused of being in league with Satan.
Convent of Sinners, Una monja en pecado, Kloster der 1000 Todsünden, La monaca del peccato (original title), Una monja en pecado, La monaca del peccato, Kloster der 1000 Todsünden
