The museum is dedicated to the years 1919-1939 and one of the galleries, the Murder Room, displays exhibits from the most notorious cases of those inter-war-years. And now a modern killer is at work, the crimes uncannily echoing the cases on display. All the small group of people, the trustees, staff and volunteers, who work in the Dupayne, have the means and the opportunity for murder. One of them the ruthlessness to kill and kill again.