Early crime fiction often invited the reader to match wits with the writer. Edgar Allan Poe invented the detective genre with his 1841 story "The Murders in the Rue Morgue," in which his hero deduces how two women were brutally slain in a fourth-floor room in which the windows and doors were locked from the inside. One of the first Sherlock Holmes stories, "The Sign of the Four," also features a locked-room mystery. Agatha Christie wrote dozens of ingenious puzzles, as did her many imitators. The genre ran into problems as plots evolved from ingenious to preposterous. By 1930, the "puzzle mystery" had begun to lose favor in America, thanks to the popularity of the pulp crime magazines and the novels of Dashiell Hammett, which in turn gave rise to the modern thriller, with its focus less on intellectual games than on violence and social realism.
The puzzle genre never disappeared, however, and Keigo Higashino's "The Devotion of Suspect X" - a bestseller in Japan and the basis of a popular movie there - is a modern example of the games a clever writer can play with his readers. At the outset, we meet Ishigami, a stout, reclusive high-school math teacher who, we are told, is a genius. He lives in an apartment building outside Tokyo and has a crush on Yasuko, an attractive woman who lives next door with her teenage daughter. Ishigami, too shy to speak to Yasuko otherwise, each day goes to the carry-out shop where she works to order his lunch from her.