If you like dark and atmospheric fantasy, you may enjoy The Book of Dead Days and its sequel, The Dark Flight Down, by Marcus Sedgwick. The books tell the story of a young orphan who knows nothing of his past and whose only name is Boy.
In The Book of Dead Days, Boy lives with the magician Valerian as a servant/assistant. Valerian has made a Faustian bargain, and if Boy and a girl named Willow can't help him find a certain book of power before New Years Eve, Valerian will be dead. In The Dark Flight Down, Boy is abducted and taken to the palace of the Emperor Frederick, where he is plunged into a world of intrigue, mystery, and danger.
Sedgwick's strength is his richly detailed word-paintings, which bring the setting and the characters to life. The books are dark, mysterious, and exciting. Both books are good, but I especially enjoyed the second one. The story was more interesting, and the character of Boy more fully developed.