The winter before he was sixteen, amateur magician Pup made a Faustian pact and sold his soul to the devil. He wasn't quite sure what he was going to get in exchange.

Pup's older sister, Dolly, is manically obsessed with her birthmark, believing it is responsible for her status as a social outcast. She becomes pathologically transfixed by Pup's dabbling in magic, desperate to believe he has occult powers that can cure her disfigurement, improve their lives, and kill their stepmother.

As Dolly's obsession grows, a young mentally disturbed Irishman lurks just around the corner, inseparable from his sharpened set of knives...

In this intense and deeply disturbing novel, Ruth Rendell explores a haunted world of obsession, delusions and murderous fantasy, with dazzling virtuosity.