In 1858 a German princess who had been recently inducted into the convent of Sant'Ambrogio in Rome wrote a frantic letter to her cousin, a confidant of the Pope, claiming that she was being abused and that she feared for her life. What the subsequent investigation by the Church's Inquisition uncovered were the extraordinary secrets of Sant'Ambrogio and the illicit behavior of the convent's beautiful, young mistress, Maria Luisa. Having convinced those under her charge that she was having regular visions and heavenly visitations, Maria Luisa began to lead and coerce her novices into lesbian initiation rites and heresies. She entered into a highly eroticized relationship with a young theologian known as Padre Peters, urging him to dispense upon her, in the privacy and sanctity of the confessional box, what the two of them referred to as the "special blessing".

What emerges through the fog of centuries is a sex scandal of ecclesiastical significance, skillfully brought to light and vividly reconstructed in scholarly detail. Offering a broad historical background on female mystics and the cult of the Virgin Mary, and drawing on written testimony and original documents, Hubert Wolf tells the incredible story of how one woman was able to perpetrate deception, heresy, seduction, and murder in the heart of the Church itself.