Since the opening paragraphs of Edgar Allan Poe’s “The Murders in the Rue Morgue”—considered by most to be the first English detective story—the genre has been about expectations. Poe practically wrote the formula at the start of his short story, outlining the logical capabilities and ratiocination of his detective, C. Auguste Dupin. Poe and later practitioners of the genre quickly established a basic pattern: damsel presents case to shrewd, all-knowing yet uncommunicative detective; detective investigates, but reveals little; detective’s friend narrates from a certain distance, guessing what’s going through the head of the brilliant detective; detective reveals all in a climactic scene that often includes some trickery and more action.
It’s a tried and true formula—one that sells despite its redundancy.
At the same time, the best detective stories are the ones that both play into and off of this pattern. What lifts The Hound of the Baskervilles above Arthur Conan Doyle’s other novels—and indeed, just about any other Sherlock Holmes short story—was its premeditated arrangement of suspects. For once, Holmes wasn’t dragging in a heretofore unknown cab driver and presenting him to the reader, sans explanation, as the murderer. Agatha Christie takes the genre a step further by playing with the narrative in The Murder of Roger Ackroyd and by eliminating the detective altogether in And Then There Were None. Dashiell Hammett and Raymond Chandler straddled the line between detective fiction and flat-out thriller with their complex cases and steel-headed Sam Spades and Philip Marlowes, respectively. A contemporary novel such as Mark Haddon’s The Curious Incident of the Dog in the Night-time works because it places the houndstooth hat on the able head of a 15-year old boy with autism.