When Lilian Jones starts at creepy, cold and bewilderingly large Shadowhall Academy, she’s nervous about making friends and finding her way around, but those turn out to be the least of her worries when strange things start happening at school. Tapping in the walls, unsettling tales of missing students, and rumours that the school is haunted. When mysterious figures start appearing at night, looking exactly like the girls themselves, Lilian suspects there may be more to the bizarre happenings than just stories, and her school is hiding real secrets. Realising her new friends could be in danger, Lilian sets out to solve the mysteries of Shadowhall Academy once and for all.