The Sherlockian, by Graham Moore

In 2004, Richard Lancelyn Green was found dead in his bed with a shoelace around his neck and a collection of cuddly toys beside him. The case, which has never been satisfactorily resolved, became international headline news because the dead man had been an expert in Sherlock Holmes. The BBC even quoted reports that the so-called "Curse of Conan Doyle" had struck again.

The fuss was a testimony to the continuing allure of Sherlock Holmes and to the world's insatiable curiosity about the great detective and his creator. Graham Moore capitalizes on this fascination to the full in his first novel, which involves the mysterious death of another British Holmesian.

The plot of The Sherlockian is also inspired by the real disappearance of a single volume of Conan Doyle's diary, covering the last few months in 1900, which has become the Holy Grail of Sherlock Holmes scholars. Seven years earlier, Doyle had killed off his hero. Holmes was seemingly gone forever after a dying fall with Professor Moriarty at the Reichenbach Falls. But, shortly after the period covered by the missing diary, Holmes reappeared in The Hound of the Baskervilles. What brought about Doyle's change of heart?

Moore's novel has a double narrative, unfolding in alternate chapters. The first is set mainly in 1900 and describes from Conan Doyle's view the traumatic and corpse-strewn events that culminated in the disappearance of the diary. Doyle's friend, Bram Stoker, plays a vital role, and so do the militant suffragettes.

The second strand takes place in the present. Harold White, an amiably nerdish Holmesian enthusiast, is inducted into the prestigious Baker Street Irregulars at New York's Algonquin Hotel. Alex Cale, a leading British Sherlockian, claims to have found the missing diary, but before he can reveal his contents, he is found murdered in the hotel. Donning his deerstalker, Harold investigates, using tried-and-trusted Holmesian methods. He also acquires a Watson in the form of an obliging reporter, Sarah, who has sneaked her way into the august gathering.

The result may not be a great crime novel, but it certainly has some witty and ingenious moments. The plot is rococo in complexity. Harold is never at a loss for an appropriate quotation from the Holmesian canon. There's also much to enjoy in the glimpses of the bizarre subculture of societies and quasi-scholarship that has grown up around the memory of the great man. A fundamental ideological split has developed: the Sherlockians, such as the Baker Street Irregulars, affect to believe that Watson really did write the Holmes stories, and that Conan Doyle was merely Watson's friend and literary agent; the rival Doyleans, on the other hand, believe that Doyle really was the author.

Much of the story takes place in London, past and present. American readers are likely to find this setting more plausible than British ones will. This doesn't really matter: As with Mary Poppins, to insist on sordid verisimilitude is to miss the point. As a writer, Moore has a light touch. Some of his descriptions verge on the Wodehouseian: "Alex's bushy light brown hair squatted on his head like a chicken laying an egg …"

Holmes haunts the book in more ways than one. The real mystery is perhaps not the missing diary or the murderer's identity but the detective's extraordinary appeal. Elementary? That's one thing it isn't. Somehow, Conan Doyle created a figure that loomed much, much larger than Doyle himself, even in the latter's lifetime. Moore gives us a glimpse of what this must have meant to Doyle. To his credit, he also gives us a glimpse of why Holmes continues to fascinate us.

Andrew Taylor's latest novel is The Anatomy of Ghosts. He is the crime fiction reviewer of the Spectator, and his website is at www.andrew-taylor.co.uk.