Thirteen-year-old Tanya has a secret: she can see fairies. However, these aren't the gentle, helpful fairies of folklore; they're malicious and torment her daily. To escape their harassment, Tanya is sent to stay with her grandmother at Elvesden Manor. While there, she discovers an old photograph of a girl who vanished in the nearby woods fifty years ago—a mystery her grandmother refuses to discuss. Teaming up with Fabian, the caretaker's son, Tanya delves into the unsolved case. As they uncover hidden truths, Tanya realizes that the manor's dark history is about to repeat itself, and she may be the next target.