The Devil You Know, the sequel to Electa Graham's first Demon Hunter novel, Heaven's Key, is not only every bit as good as its predecessor, it's even better. With new locales, strange and creepy characters, Medieval history, ancient ruins and ghostly occurences, the hunters Jael and Cole are back and in search of the missing pages of none other than the Codex Gigas itself. Cain, the son of Lucifer also makes a return, and somehow it's difficult not to like and somewhat empathise with such a chaotic and damned character. Electa Graham is on top form with the second novel of the Demon Hunter series. The central characters are a joy to revisit. If you liked Heaven's Key, you'll be missing out if you don't read The Devil You Know. If you haven't yet read Heaven's Key, then you should do that first, and NOW.