Kingdom of Naples, 1577: The Roman Inquisition and the witch hunt are in force and torture is authorized in the trials, while the people live in misery and fear. The handsome Spanish nobleman Don Carlos enjoyed it in the convent of Sant'Arcangelo di Baiano, satisfying his eroticism with Sister Giulia di Mondragone, a powerful ecclesiastic who aspired to the title of abbess of the convent. Having evaluated the power of Don Carlos, Giulia tries to please him, while other sisters, especially Sister Carmela, plot against her as interested in the coveted title of abbess. Giulia offers herself on several occasions to Don Carlos, despite being a lesbian and eager to be alone with her sweetheart: Sister Chiara. Giulia pleases Don Carlos even when he asks her to spend a night of love with the beautiful young Sister Isabella, Giulia's niece, forced against her will to take the monastic vows but, in reality, very much in love with a boy from the country 'origin. Considering that the current abbess, Sister Lavina, appears to be ever closer to death, Giulia and Carmela go wild in a war that will have to determine who, on Lavinia's death, will succeed her in her duties and functions. From pure actions moved by jealousy they pass to poisonings, traps, complaints and false accusations. If Sister Giulia favors Don Carlos, Sister Carmela, even through some protectors and lovers, she reveals a criminal conduct at least equal to that of Giulia. The step towards the scandal is short: deaths, threats and beatings accompanied by the sending of anonymous letters to the high ecclesiastical authorities, immediately open a trial. The vicar Carafa, representative of the Inquisition sent by the Archbishop of Naples, deals with the scandal: the ruthless process in which various sisters are tortured and made to confess.