Isobel lives an isolated life in North London, working at a nearby library. She feels safe if 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 are all it takes for her ordinary, careful armour to become overwhelmed and the trauma of what happened when she was a pupil at The Schoolhouse to return. The Schoolhouse was different, one of the 1970s experimental schools that were a reaction to the formal methods of the past. The usual rules did not apply, and life there was a dark interplay of freedom and violence, adventure and fear. Only her teenage diary recorded what happened, but the truth is coming for her and everything she has tried to protect is put at risk.