Parallel plotlines set in different times, one told in text and one in art, inform each other as a young girl unravels the mystery of a ghost next door.
1982: Mary is a lonely orphan at the Thornhill Institute For Children at the very moment that it's shutting its doors. When her few friends are all adopted or re-homed and she's left to face a volatile bully alone, her revenge will have a lasting effect on the bully, on Mary, and on Thornhill itself.

2016: Ella has just moved to a new town where she knows no one. From her room on the top floor of her new home, she has a perfect view of the dilapidated, abandoned Thornhill Institute across the way, where she glimpses a girl in the window. Determined to befriend the girl, Ella resolves to unravel Thornhill's shadowy past.