Lilith Ripinski is a 15-year-old loner, with an annoying 17-year-old brother named Samuel. One day, he pushes her just a little bit too far, and they enter into an intense, surreptitious sexual relationship. "The Book of Lilith" chronicles the development of their incestuous dynamic, their struggle to keep it secret, and the way Lilith's confidence grows as a result of feeling desired for the first time.
Her grandfather saved the life of a lord and now she makes the long journey from the north of England to Shropshire to his manor in the hope of being offered a position in his household. The old Lord is dead but his son takes her in.