Thaniel, just seventeen, is a wych-hunter. Together, he and Cathaline - his freind and mentor - track down the fearful creatures that lurk in the Old Quater of London. It is on one of these hunts that he first encounters Alaizabel Cray. Alaizabel is half-crazed, lovely, and possessed. Whatever dreadful entity has entered Alaizabel's soul has turned her into a strange and unearthly magnet - attracting evil and drawing horrors from the very depths of hell. Cathaline and Thaniel must discover its cause, and thus begins a treacherous quest across London. At stake is all humanity. Chris Wooding has created a host of dramatic and memorable characters in this extraordinary, cinematic novel.