Isobel lives an isolated life in North London, where she works at a nearby library. She feels safe, so long as she keeps to her routines and doesn’t let her thoughts stray too far into the past. But a newspaper photograph of a missing local schoolgirl and a letter from her old teacher send her spiralling and bring back the trauma of what happened years ago, when she was a pupil at The Schoolhouse.
The Schoolhouse was a 1970s experimental school where Isobel’s days were a dark interplay of freedom and adventure, violence and fear. The only record of what happened there lies in the pages of her teenage diary. The Schoolhouse taught Isobel that some truths must never be revealed, but as police investigating the missing girl start to ask uncomfortable questions, she realises the truth is coming for her – and it will put her, and everyone she has tried to protect, at risk.