It all ended in a single word.
Three years to the day after Sherlock Holmes tumbled off a rooftop and disappeared from the world, John Watson knelt at his gravestone, a bouquet in his hand.
"I should probably stop doing this," said Watson, in a tone which grew more resigned every year. "They say I'm only tormenting myself. That I'll have to grieve all over again when I finally do accept that you're gone – 'when', not 'if', they say." He snorted derisively. "'When'. It's all bullshit, Sherlock. I said when you left that I'd never stop believing in you. And I never will."
Watson stared at the gravestone for a moment, the black stone shining in the sunset. "I don't care what they say!" he cried, in a fit of sudden anger. "I don't give a damn. I can't believe it. I won't believe it. Not now, not ever."
He shook his head, almost as if he was astounded by his own stupidity. "But when does it end, Sherlock? When do you come back to me?"
"Now."
Watson whipped around at the sound of the voice, dizzy, almost desperate, but the trees blurred in his vision, and he could make out nothing but the light and shadow of the wood that surrounded them. He made an agonised noise in the back of his throat, savagely kicking an inoffensive clump of grass, ready to cry, to rage, to scream…
"Surely you couldn't imagine," continued the voice, "that I could ever leave the best thing that ever happened to me."
"Damn it," whispered Watson, "don't do this. This isn't fair. I can't…"
"Look up, John."
John did, at last, and a particularly deep patch of shadow coalesced into a black trench coat and a pair of vibrant, pale eyes John Watson could have recognised in the darkest depths of space.
"Sherlock?" he whispered, uncertain, and staggered back against the gravestone. His breathing was harsh and ragged, tearing at the lining of his throat and burning in his lungs.
"Well of course it's me, you idiot," said Sherlock impatiently, "who else would throw themselves off a building to save you from a pack of Moriarty's hired snipers? Oh, and save Lestrade and Mrs Hudson too," he added, if only for the sake of completeness.
"Excuse me," said John, "I think I need to sit." And he dropped unceremoniously to the grass.
Amused, Sherlock followed, still a handful of metres away.
"Snipers," said John, disbelieving. "Snipers. Why would he – me?"
For the first time since he'd stepped out of the trees, Sherlock turned serious.
"Surely you cannot be so thick, John, as to not have realised by now that you are the only living being I care about?"
Anger flared, hot and sudden and far, far overdue. "Then what the fuck are you doing sitting not five metres from me, you imbecile? For all you know, he could have a sniper's rifle trained on me right now! He – "
"John."
" – was the bastard who took you away from me, you jackass, and don't think I'm not furious with you for that! I thought you were dead! I didn't want to believe it but I spent three years thinking you'd died on the pavement at St Bart's, because I learned long ago that if wishes were horses I'd be the Queen! I had to live without you, you utter pillock, and if you're going to make all that worthless then – "
"John!"
"What?"
Sherlock fixed unblinking eyes on the outraged man in front of him and cut his tirade abruptly short. "It's over, John. It's all over. I finished it. I finished it in Germany three days ago and hopped the next Eurostar home because it had been three years and I was done."
John didn't blink. "So you finished it and came home. Just like that."
"No, you moron, I finished it so I could come home to you."
That was all she wrote. John launched himself across the grass separating them; they landed in a tangle of limbs and gasping breath as John wrapped his arms around Sherlock and just held on.
"Aren't you going to ask how? Ask why?" Panting, desperate, Sherlock clutched his friend close.
"Don't care," muttered John into the wool of Sherlock's overcoat. "Find out later. It's over. You're here. Don't care about anything else."
Wordless, Sherlock dragged him closer, felt John begin to shake in his arms, and knew beyond a doubt that this was worth coming home for a thousand times over.
Trembling, undone, John Watson began to cry.
He cried for quite some time, messy and incoherent, and Sherlock – blessed Sherlock, how far he'd come! – held him through it all.
And then John looked up into Sherlock's eyes, so pale and glorious, and he smiled, and the sun shone on Sherlock Holmes for the first time in three years.
"I always believed," said John fiercely. "I always believed in you, Sherlock. Always."
"I know you did, John. Do you think I could have won, if I hadn't had you? You won this battle, John, not me, because you gave me something to fight for." Sherlock looked at him quite seriously for a moment. "I told you once that as a conductor of light you were unbeatable. But these three years – John, I didn't know how true those words were until I had to leave you behind. These three years have been grey and dark without you, and – and I finished this so I could come home. Come back to my light. Come back to you."
John made a broken noise against Sherlock's coat.
"John… please, John. Say something."
"I am so angry with you," John says at last. "I am so fucking angry with you, Sherlock Holmes, because I watched you die on the pavement, and that sight will haunt me for the rest of my days. I am so goddamn angry with you, Sherlock, for leaving me behind. But damn you, right now I don't give a flying fuck what you did or why you did it because I am just so fucking grateful you're alive, so for the love of God, Sherlock, kiss me!"
He hadn't planned to say that last bit. Hadn't known he wanted to say it until it came spilling out of his mouth. But he can't unsay it, and wouldn't even if he could. This has been built in gunshots and blood, tears and laughter, fear and fury and a kind of relationship neither of them knew existed before 221B Baker Street, this friendship that became love too strong to deny.
They've crossed the Rubicon, and there is no going back.
Sherlock froze. "John," he said, and something in his voice made John's knees just melt. "Be sure. Please. Because it has only ever been you, and if you are not serious about this…"
"Not serious?" John choked. "Sherlock, I've built my fucking life around you. I… God. I have never been more sure of anything."
They kissed then, messy and open-mouthed and frantic, and it should be new and frightening but it's not, it's just something that's been too long coming. John mapped the curve of Sherlock's lips, traced the planes of his face, tangled his fingers in Sherlock's curls as Sherlock's hands wander everywhere, trying to memorise everything all at once. They'll have to move this to the bedroom soon, very soon, so they can let this run where it may and learn each other in a way completely different to anything they've ever learned before.
But they'd waited three years. They could wait another thirty minutes.
"John," said Sherlock when they can finally tear their lips apart, and God, the way he says John's name will never not be the sexiest thing John Watson has ever heard, "you do intend to come home, don't you?"
"You idiot," said John, and Sherlock smiled.
They're going to be all right. John will yell and scream and scold, and Sherlock will nod and murmur apologies and promise to never leave John behind again, and John will huff and say it will do for now, and then he will follow Sherlock just as he's always done, because he never really stopped believing, and it will be a lesson to Sherlock in the power of love and the power of faith.
But here in a sunlit graveyard, all they know is that they've found each other.
Sherlock braced his hands on John's shoulders. "You've seen a bit of trouble, I take it."
Oh, God, John's grinning like a bloody schoolgirl, because only Sherlock, and that's the end of it, isn't it? Only Sherlock.
"Of course, yes. Enough for a lifetime, far too much." Could John's smile get any bigger?
"Want to see some more?" Well, apparently, yes it could, because Sherlock Holmes is holding out his hand and the greatest adventure of his life is right in front of his nose.
John Watson grabs it with both hands.
"Oh, God, yes."