The first book in a spine-tingling mystery series set in a creepily atmospheric boarding school. When troublesome Scarlet mysteriously disappears from Rookwood School, terrifying Miss Fox invites her quiet twin sister Ivy to 'take her place'. Ivy reluctantly agrees, for only at Rookwood will she be able to unlock the secrets of Scarlet's disappearance, through a scattered trail of diary pages carefully hidden all over the school.