“It Was the Mark of Cain”:
Agatha Christie and the
Murder of the Mystery
When Agatha Christie killed Hercule Poirot, both she and the detective novel were in their prime. But even in the 1940s, when she wrote Curtain, Christie portrayed, and in a sense foresaw, a new kind of crime that would lie beyond the detective's control. That new crime was motiveless murder. By the mid1970s, when Curtain was finally published (along with Miss Marple's less sensational last case, Sleeping Murder), motiveless murder was fast becoming a new and intense focus of the public's fear of crime. And a new genre had appeared: the true-crime novel, which was largely concerned with random murder and replaced the detective novel on the cutting edge of popular crime literature. Curtain looks ahead to this genre by presenting as its villain a psychopath who kills without any apparent reason. Poirot defeats this killer and restores order, as he does in so many detective stories. But he does so only at the cost of his own life and that of the detective figure himself, thus changing the terms of the murder mystery and leaving the field to a new kind of crime fighter and crime writer.
In order to understand the importance of Curtain and the bridge it builds to the new nonfiction genre, we must first place the detective story in context not only with the true-crime story that follows it but also with the early criminal biography that precedes it. The criminal biography—comprised largely of gallows broadsheets, The Newgate Calendar, and Newgate novels—flourished in the eighteenth and nineteenth centuries, when crime and punishment were particularly vexed subjects and the public spectacle of execution demonstrated England's deterrent approach to law enforcement. As has been often noted, the biography presented crime in an ambiguous and discomforting manner. First, it often showed criminal life as romantic (especially when it concerned such crowd-pleasers as Jack Sheppard or Dick Turpin—the latter most lately seen in