In December 1893, the Strand Magazine - a hugely popular monthly - published The Final Problem. This is how it ended:
“A few words may suffice to tell the little that remains. An examination by experts leaves little doubt that a personal contest between the two men ended, as it could hardly fail to end in such a situation, in their reeling over, locked in each other's arms.
“Any attempt at recovering the bodies was absolutely hopeless, and there, deep down in that dreadful caldron of swirling water and seething foam, will lie for all time the most dangerous criminal and the foremost champion of the law of their generation. (Sherlock Holmes) I shall ever regard as the best and the wisest man I have ever known.”
And that's where Conan Doyle wanted to leave Sherlock Holmes. He was bored with the character. It annoyed him that this quirky creation overshadowed everything else he wrote.
He wanted to be remembered as a writer of serious historical fiction, yet his career seemed to be hitched to the bandwagon of Holmes's ever-increasing popularity in a monthly magazine.
So he did something extraordinarily courageous for a young, still-finding-his-feet author — he killed off the golden goose. Not by retiring him, or marrying him off, but by pushing him headlong into a Swiss waterfall.
But Sherlock Holmes had already taken on a life of his own. He was bigger than Doyle and more popular than anything else he was writing.
Doyle resisted increasingly generous offers from The Strand for a number of years, although he did give them The Hound of the Baskervilles in 1901, set before Reichenbach.
Its huge success, plus Doyle's need for money to fund other projects, delivered the 'resurrection' of Holmes in 1903, with Doyle writing another 32 stories between then and 1927.
The 'cult' of Sherlock Holmes began that December, 120 years ago, and shows no signs of wearing off. At the moment Robert Downey Jnr., Jonny Lee Miller and Benedict Cumberbatch are enjoying huge success with three entirely different interpretations and reinventions of the character.
The books have never been out of print. He has appeared in more films and television and radio programmes than any other character: not too mention plays, musicals and even a ballet.
He's one of the biggest brand names in the world: up there with Disney, Coca Cola and Microsoft. When shown just the outline of a deerstalker and Meerschaum pipe people anywhere in the world with access to books and television can name him.
And that's because Holmes doesn't live in some sort of limbo: rather, he is an omnipresent and unstoppable life force. Holmes is more than Hamlet, Lear, Othello, Fagin, Heathcliffe, Don Quixote, Robinson Crusoe, Harry Potter, Mr Darcy, Robin Hood, Mr Pooter, Jeeves, Ivanhoe, Captain Ahab, Atticus Finch, or any of a hundred other characters who, once encountered, stay somewhere in what Holmes would have described as “our brain attic”.
All of these characters are of their time. Yes, we may quote them and remark about how well they have stood the test of time and how they can be returned to again and again: but you don't have to return to Holmes, for Holmes is here with us.
You couldn't lift Hamlet and give him new words to say, because the character would no longer work. You couldn't find an undiscovered, unmapped place for Robinson Crusoe; Sherwood Forest is a tourist trap; whaling is outlawed; civil rights legislation has put Finch out of business; and Harry Potter has grown up and married.
Even Star Trek's Mr Spock, who claims — or at least I'm pretty sure he did so in one of the feature films — to be a descendent of Sherlock Holmes, is firmly trapped and locked within his own parameters.
Holmes is more than Batman, Superman, Spiderman, or any of the other comic book heroes who don a disguise and mask to tackle villains and put the world to rights.
They are always pitted against fabulously wealthy megalomaniacs who, lacking the intellect of a Moriarty, or the ability to employ henchmen who can shoot straight, tend to come crashing to earth by way of a massive explosion, or a collapsing dam.
Let's be honest: these soi-disant do-gooders wouldn't recognise a first, let alone a second, stain at the scene of a crime and their idea of the Red-Headed League tends to be the Joker's cronies in fright wigs. We remember them from our early years of reading, but most of us have the good sense to pack them away with our other childish things.
Holmes is more than Frankenstein, Quasimodo, Dracula, the Incredible Hulk, the Phantom of the Opera, Mr Hyde, Hannibal Lecter, or even Freddy Kruger. They are all one-trick ponies, who may have you scurrying behind the sofa or beneath the duvet when you first meet them, but it doesn't take long to realise that they are all just glorified bogymen.
Put them in a normal setting and they would soon be locked up, or laughed back into that half-remembered world which parents conjured up to get us to stay firmly in bed once the lights were out.
Holmes defies the constraints of time, dimension or circumstance. Like Doctor Who, he is capable of being put in any place at any time. But, unlike the Doctor, he is human and always the same Holmes in the same form.
It is Holmes' ability to defy time and circumstance which explains both his durability and flexibility. From adverts to wartime propaganda; from rebel to role model for just about every other detective; from quirky loner to international icon; from Baker Street in 1895 to Baker Street in 2014 and beyond.
He has done it all. Come back from the dead, been transported to the 22nd century, defrosted in the 1970s, done battle with the Kaiser and with Hitler, dealt with Jack the Ripper and the Loch Ness Monster, disrupted Irish republicans, sailed on the Titanic, helped Father Dowling overcome a crisis of faith, been a source of inspiration for Wesley in By The Light Of The Silvery Moon and spoken in just about every known language. The police services even deploy the Home Office Large Major Enquiry System (Holmes2) computer database to assist with big investigations.
Can you imagine Lear, or Don Quixote, or even Doctor Who doing all of that?
The writer Sebastian Faulks argued that “Sherlock Holmes was perhaps the purest example of a hero-as-main-character that a British writer has contrived. Holmes has aspects of the demigod. We don't know if he was held by his heel in a river of immortality, or formed on the planet Krypton, but he behaves as though something of the kind had happened in his youth.”
Sherlock Holmes is imperious, infuriating, impish, cold, detached and stupendously arrogant. But he's also gentle, warm, funny, engaging, kind, fiercely loyal and incorruptible.
He is a genuine one-off, the template for almost every other detective who followed. The logic doesn't always hold up to close examination and he relies on simple hunches on far more occasions than he would be happy to admit to. But none of that seems to matter to each new generation who read about or watch him.
For many, though, Holmes' greatness and timelessness rest on his thirst for justice and the enormous depths of his compassion. Those qualities are timeless and so, too, is humanity's desire to embrace their ongoing existence.
Sherlock Holmes lives because of what he represents and because we — all of us — need someone to champion those qualities anywhere and always. Holmes is everyman writ large: that one person we would want at our side when all else had turned against us. He lives. And he probably always will.
Sherlock, BBC1, New Year’s Day, 9pm
A life so far
Sherlock Holmes appeared for the first time in 1887, in A Study In Scarlet
Originally Conan Doyle was going to call him Sherrinford Holmes (with Dr Ormond Sacker)
Holmes never did say “Elementary, my dear Watson.”
He has featured in more films, television and radio adaptations than any other person: the first film in 1902
There are many Sherlock Holmes societies across the world, including Northern Ireland
Society members play The Great Game - beginning with the premise that Holmes and Watson are real people