Detective Inspector Hanlon has been promoted, and is undercover in Oxford to find the sadomasochistic killer of two students. Philosophy lecturer Dr. Gideon Fuller, with his penchant for high end sadistic sex, is in the frame, but Hanlon is not convinced. From the specialist brothels in Oxford and Soho, to the inner sanctum of a Russian people trafficker with a taste for hurting women, the trail leads Hanlon deeper and deeper into danger—until she herself becomes the killer's next target.