The castle was moonlight-vast, all its ages fused together by the shadows, chimney stacks like the backs of hands turned black.

Hay-on-Wye: a eccentric medieval town known for its dozens of secondhand bookshops. and for having its own king. Now in the grip of recession, Hay is fighting for its future. Not the best time to open a bookshop, but Robin and Betty are desperate, and only Betty worries about the oppressive atmosphere of the shop they’re renting.

Merrily Watkins, diocesan exorcist for nearby Hereford, knows little about Hay until a body is found in the dark pool below a waterfall on the outskirts of the town and the police ask her to assist. The dead man’s peculiar interests will open a passage to the hidden heart of Hay and a secret history of magic and ritual murder. And Merrily is alone and vulnerable as never before.