The year is 1955, the location picturesque Devon. In a house by the River Dart, schoolgirl Josephine Kennedy posts invitations to her twelfth birthday party - a party that never takes place. Horrific violence is committed that night in the family home, leaving all of its occupants dead. Based on a disturbing real-life crime, this compelling story explores Josephine's fate through the prism of friends and family - the victims and survivors who unwittingly influenced the events that led up to the tragedy. Josephine's best friend, Susan, is haunted by the secrets of the birthday house. Can she ever find a way of making peace with the past?