Britain's Mark Haddon is best known as a children's author, but many years ago he used to work with autistic children, and the experience is the basis for his first adult novel, just preempted by editor-in-chief Bill Thomas at Doubleday after a string of European sales at auction. The book is The Curious Incident of the Dog in the Night-Time, and if that sounds like a Sherlock Holmes sort of title, it's because the book's hero, young Christopher Boone, is obsessed with Holmes. He is also an autistic savant and the narrator of this tale about how the death of a neighbor's dog leads him to unravel the truth about the collapse of his parents' marriage. The book has already been sold, by London agent Clare Alexander at the Gillon Aitken agency, to half a dozen countries as well as the U.K., and Thomas, after his North American buy, sold the rights to Maya Mavjee at Doubleday Canada. Haddon's novel will be published next June.