Ambrosio, a pious monk, finds himself drawn to his pupil, Matilda, a young woman in disguise. Unable to control himself, he sates his lust, and soon tires of her. But Matilda has more than her body to offer. As his desperate acts become more and more depraved, it becomes clear that Matilda is not everything she seems.
Looking for more like this? See books like The monk.
Severity reflects intensity, not value -- “central theme” means a warning is a core part of the book, not that the book is bad.