Commander Adam Dalgliesh is already acquainted with the Dupayne Museum in Hampstead and its sinister murder room celebrating notorious crimes committed in the interwar years when he is called to investigate the killing of one of the trustees. He soon discovers that the victim was seeking to close the museum against the wishes of both staff and fellow trustees. Everyone, it seems, has something to gain from the crime. When it becomes clear that the killer is prepared to kill again, inspired by the real-life crimes from the murder room, Dalgliesh knows that to solve this case he has to get into the mind of a ruthless killer.

P. D. James was a bestselling and internationally acclaimed crime writer. She was the creator of Adam Dalgliesh and Cordelia Gray, and their long and successful series of mysteries. Her works include Cover Her Face (1962), An Unsuitable Job for a Woman (1972), Innocent Blood (1980), Children of Men (1992), and the Jane Austen-inspired Death Comes to Pemberley (2011). James was born in Oxford in 1920. She won awards for crime writing in Britain, America, Italy, and Scandinavia, including the Mystery Writers of America Grandmaster Award. She received honorary degrees from seven British universities, was awarded an OBE in 1983, and created a life peer in 1991. In 1997, she was elected President of the Society of Authors and stood down from this role in 2013.