When Adam Salton arrives at his grand-uncle's Derbyshire estate he quickly senses that a macabre and malevolent force is at work. In his attempts to uncover the grisly mystery he encounters the chilling Lady Arabella and the obsessive Edgar Caswall, each harbouring their own dark and dreadful desires. To his horror, Adam discovers that something hideous is living in the grounds of nearby Castra Regis, something that feeds on the flesh of humans. And so begins a terrifying quest to destroy the evil lurking in their midst.