A dark fantasy set in a parallel London stalked by demons...London has survived war and plague only to face a new horror - the Wych Kin.

All kinds of demons lurk in the labyrinth of the Old Quarter, and it is the task of wych-hunters such as Thaniel Fox to keep them at bay.

Then one night he rescues a young woman who has lost her memory: the beautiful and vulnerable Alaizabel Cray.

But Alaizabel is nursing a dark secret, one that even she does not understand, a secret that could unleash the most terrible evil of all...