The late 19th century witnessed a particularly gruesome crime. An impoverished Scottish doctor, struggling to maintain his working-class general practice in Southsea, gave birth to a prodigy, whom he then tried brutally to kill.
He carefully researched the means of death, selecting the picturesque Reichenbach Falls in Switzerland. The murder was a purely literary one, and no arrest was made.
But the attempted homicide had the opposite effect.
It seems to have given Sherlock Holmes an unnatural extension of life -- to make him, indeed, immortal.
Arthur Conan Doyle reluctantly brought him back from the dead, and over the remaining 30 years of his life wrote a number of novels and short stories, generally when he needed the money.
Holmes had already taken on a life of his own.
Indeed, when Doyle sent the great detective plunging to what he hoped would be his watery grave in The Final Problem, readers were so outraged that they stood outside the writer's house in solemn protest, wearing black arm bands.
For them, he was real.
Already by then, 1892, Holmes had slipped his creator's leash. Holmes stories written by other hands than Doyle's were in widespread circulation.
And when, at Doyle's own suggestion, the American actor William Gillette wrote a play loosely based on a number of the Holmes stories, the actor took certain liberties, egged on by Doyle, that changed the popular perception of the character.
Gillette endowed him with the famous meerschaum pipe and the deerstalker hat, and gave him his most famous line: "This is elementary, my dear Watson." These three things are what most people first think of when they think of Holmes, and they are nothing to do with Conan Doyle. In his latest incarnation he's interpreted with homo-erotic overtones in Guy Ritchie's new film.
Like Chekhov, Bulgakov and Somerset Maugham, Doyle was a doctor, and he saw that the old diagnostic skills -- the close observation of behaviour, of physical condition, of speech patterns -- allied to forensic analysis were the very stuff of detective fiction.
His masterstroke -- or perhaps his best stroke of luck -- was to have a model in which he could embody these principles in the compelling personality of his charismatic teacher at Edinburgh University, Joseph Bell.
According to Doyle's auto-biography, Bell "would sit in his receiving room with a face like a Red Indian, and diagnose the people as they came in, before they even opened their mouths. He would tell them details of their past life; and hardly would he ever make a mistake." It is this -- raising the power of rational thinking to the point where it becomes almost magical, positively shamanistic -- that is so spellbinding. Ever-increasing levels of bafflement create a tension in the reader that is finally, orgasmically, released in the mounting excitement of explanation.
Doyle's Sherlockian output is relatively slender: four novels and five volumes of short stories. The best of them -- The Hound of the Baskervilles, for example -- remain thrilling: atmospheric, eerie, ingenious.
Holmes himself is darkly brilliant, and quick with aphorisms. "When you have eliminated the impossible, whatever remains, however improbable, must be true." The cast with which Doyle surrounded Holmes -- his even cleverer brother Mycroft, Inspector Lestrade, the diabolical Moriarty, the admirable Watson -- are three-dimensional and entertaining.
But it is the personality of Holmes himself that has always been the focus. Gillette went on playing the part on stage until his late 70s; by then the character had become a film star, in the -- to some, definitive --form of Basil Rathbone ("two profiles", as Orson Welles memorably remarked, "in search of a face"). The 14 films in which he appeared were taken from Doyle, as were those in which the deerstalker was assumed by a cadaverous Peter Cushing.
A nobly questing Douglas Wilmer played Holmes on television for years, and then a radical new interpretation transformed our view of the character.
The superbly handsome Jeremy Brett, the regularity of his features made dramatic by a broken nose, the mellifluousness of his voice made arresting by a slight vocal impediment, presented a ravaged and romantic Holmes, a man who had suffered deeply and whose recourse to the syringe was the compulsion of a self-destroying temperament. His relationship with Edward Hardwicke's transparently decent Watson was that of a drowning man clinging to a raft.
The authenticity of the performance was unmistakable.
It's unlikely that Ritchie's Holmes, Robert Downey Jr, will please all the vast army of Sherlockians, members of the Baker Street Irregulars, the Shades of Sherlock, the Amateur Mendicant Society, the Persian Slipper Club andDr Watson's Neglected Patients, all of whom believe that that they know Holmes personally. A stroll down Baker Street reveals them in all their barking madness, visiting the shrine of someone who existed only on the printed page.
The most fascinating modern manifestation of the great detective is surely in the television series House, which is a systematic transposition of virtually every element of the original. House, like Holmes, is addicted to morphine, he has an awkward relationship with women, and has a decent, solid sidekick.
It is satisfying to think that this radical reinvention of the character brings us right back to the hospital wards in which it all began, and the sombre figure of Joseph Bell.
It will scarcely be the last transformation of the character who would not die.