Tanya is no ordinary girl. She can see fairies. But not the fairies we imagine. Evil fairies who cast spells on her, rousing her from her sleep and propelling her out of bed. At wit's end with her daughter's inexplicable behavior, Tanya's mother sends her away to live with her grandmother at Elvesden Manor, a secluded countryside mansion on the outskirts of a peculiar Essex town.

There is plenty to explore, as long as Tanya stays away from Hangman's Wood - a vast stretch of forest, full of catacombs and notorious for people losing their lives. Fifty years ago a girl vanished in the woods, a girl Tanya's grandmother will not speak of. As Tanya learns more about this girl, she finds herself dangerously close to vanishing into the fairy realm forever.