The historian tells the story of one of the first high-profile killers - Dr Crippen, who was hanged in 1910 for poisoning and dismembering his wife - before turning her attention to the interwar period, when detective fiction reached the peak of its popularity at the hands of authors Agatha Christie and Dorothy L Sayers. After undergoing the elaborate initiation ceremony of the Detection Club, which was set up by a group of British writers in 1930, Lucy considers how Alfred Hitchcock's films and Graham Greene's books eclipsed the traditional murder-mystery story in the depiction of homicide.