Note: Written for a prompt on the kink meme asking that John secretly be a unicorn, and Sherlock a virgin, with John being understandably protective/possessive. Not crack.
Disclaimer: The characters of Sherlock are not mine, nor is the story, nor are the characters from the original stories by Sir Arthur Conan Doyle. I make no monetary profit from this. I also acknowledge heavy borrowing from Peter S. Beagle's The Last Unicorn and Michael Green's De Historia et Veritate Unicornis and The Book of the Dragontooth.
De Veritate Unicornis Modernus
(On the Truth of the Modern Unicorn)
Out of the hidden gulfs I made thee, free and by form unbounded. Wilt thou accept shape upon Earth, that thou mayst supply a service even greater? - The Unicornis Notebooks of Magnalucius
They were thought to have gone the way of the sphinx and the manticore, if they were thought of as having been real at all. They were not forgotten though, not like so many of the old gods, but then, also unlike the gods, their continued existence was not dependent on the sustained belief of human beings.
This, he knew, was a good thing. In the present day and age, all a unicorn was supposed to be was a horse with a horn.
It wouldn't have bothered him so much if it hadn't been horses, with their inelegant noise and heavy feet. He wouldn't have compared unicorns to any earthly animal at all, to be honest. The people who knew what they were talking about compared them to goats, to deer, to particularly graceful gazelles and antelopes, but even that fell dreadfully short of the mark.
Unicorns were unicorns, defined by - but so much more than - their possession of a single, spiral horn, and that was all there was to that. End of story.
Well, not really, not end of the entire story as such. Even unicorns had to change with the times, to learn to walk amongst concrete and steel and smog, to live with taxis and the Underground and aeroplanes.
He missed the old days of course, but he didn't find the present day strange. He had seen it grow up, so to speak, from the days of fire and the wheel, and so he was accustomed to the world as it was now, though every now and then he would come across a something new, an invention or some such thing, that would make him raise an eyebrow and wonder whatever mankind could possibly think of next.
It was, however, getting harder to find people to choose and to cherish. This was their primary function, the purpose for which they had been created: to guide people to the right path, to stay in the light, to help them, in other words, to walk the straight and narrow. It could be argued that they ought to be there for the people who needed saving, those who had fallen and needed more than a nudge in the right direction. And to this he would say, well, yes, but you needed to be pretty damn special to get a unicorn, just the right kind of person, even if you had fallen a little ways, and there were other beings for those who were in need of a greater amount of salvation.
And being a virgin was still a prerequisite. So was a certain degree of innocence.
He hadn't had many charges in the twentieth century. The twenty-first century had found him one Harriet - Harry - Watson, who had been beautiful and brilliant until she discovered women. And alcohol. She had cried when she realized that he was gone, and maybe that was when she started to truly come undone, and maybe it wasn't. But she had lost her unicorn, and he couldn't come back, not even to reproach her with his sad, ancient eyes.
The unicorn mourned the loss of his Harry and all that she could have been, in his way. Unicorns can sorrow, but they cannot regret, and he could only move on.
William Murray, Bill, had been found fairly quickly afterwards, which was practically a miracle in itself. He had some small magic of his own, an easy, open smile, and a constant sense of bewildered wonder at the fact that he merited a unicorn. He would reach out to touch the unicorn when it showed itself to him, his fingertips only just brushing the white coat, worshipful and just enough to confirm that yes it was real. This flattered the unicorn, or pleased him, rather, to put a nicer word on it.
Bill had not expected the unicorn to follow him to Afghanistan. He had, in fact, tried to dissuade him from coming, certain that he would lose the unicorn there, one way or the other, and he didn't think he could bear it if he did. And the unicorn had told him that, bugger all, what kind of guardian did he think he was? He had walked with warriors before, and it was his job to keep Bill Murray safe. Mostly to keep him good, but safe was also a pretty high priority.
The unicorn wondered, much later, if it had been a near-terminal attack of hubris that had driven him then. He was, though immortal, much less than divine, and open to temptation. If unicorns had any sin at all in them, it was pride. Pride and vanity. For what greater feat was there than to keep a man innocent in the midst of battle? And who better to accomplish that than this one unicorn and his Bill Murray?
Things went well until they met the dragon.
It was on no-one's side. Bill's unit came across it in the desert one night, and it would have left them alone - for mankind does not need dragons to do evil, and it was content to live on the chaos and carnage of a pointless war - if it hadn't seen the unicorn.
The unicorn and the dragon are natural adversaries. There is nothing a dragon delights in more than the destruction of a unicorn, the dimming of a light placed by the Creator on the Earth.
Men died in the moment when the unicorn stood frozen in horror and disbelief. And more would have been killed if the dragon hadn't stopped to roar his triumph in a sound that shook the stars in the sky. (Dragons are also guilty of conceit.)
He charged as the dragon gloated, horn lowered, aiming for the monster's heart. Bill was still alive, and the unicorn was damned if he was going to let his charge die by dragon-fire.
The dragon lowered its head on its long, serpentine neck and locked its gaze on the figure galloping towards it across the sands. The eyes of the two creatures of legend met, and things began to look very bad for the unicorn. For one of his kind, there is no more deadly trap than to look into the eyes of a dragon and know darkness and despair.
The unicorn stood, unable to move, in front of the dragon, small and white, the brilliance of his horn lost in the smoke and flames of the beast's breath. He knew he was lost.
And then Bill Murray worked the greatest and last magic that he would do in his life.
There had been a real John H. Watson, Harry's brother, who had, by complete coincidence, been a friend of Bill's in the army. He had been an essentially good man who had done his quiet best, and, to be honest, the unicorn would have chosen to follow him rather than his sister if he hadn't lost his virginity and his innocence at fifteen (the girls liked John Watson, oh yes they had, and John Watson had liked them, oh yes).
He had died that night, burned out of existence by dragon-fire when he threw himself at the monster in an attempt to save his unit. A good man, a hero, if the unicorn had ever known one. And a complete life to step into.
Things could have been worse.