Cormoran Strike is extremely worried when a troubled young man named Billy approaches him for assistance in looking into a crime he witnessed as a youngster. Although Billy is definitely experiencing mental distress and has trouble recalling specific specifics, there is something sincere about him and his account. Billy, however, flees from his office in a panic before Strike can question him any further. Strike and Robin Ellacott, who was once his assistant and is now a partner in the agency, set out on a convoluted investigation to learn the truth about Billy's case. Their path takes them through the shadowy corridors of Parliament and to a stunning but sinister manor house in the middle of the countryside.