Title: Human Error
Characters/Pairings: Sherlock, John
Genre: Romance, Angst
Ratings/Warnings: PG
Summary: Silly John. Did he ever know? Did he need everyone to spell it out for him?
Disclaimer: I do not own the BBC adaptation of Sherlock.

Human Error

They are standing on an airfield, wind whipping through their hair. The private jet awaits Sherlock; it sits there like the elephant in the room. The inevitable parting. And Sherlock takes it with grace, asking for a moment alone with John.

It's funny how, at this crucial moment in their lives, they have nothing to say to one another. Though that's a lie, Sherlock knows, because there's plenty they could be saying, and none of it... suitable.

He got too involved. His heart was on the line. Stepping back into John Watson's life after those two years was a mistake, and that mistake leads to now, to an airfield on a cloudy day. And the east wind's blowing, coming to take him away.

John's like Redbeard in a way, loyal and friendly and always by his side. He lost Redbeard. He lost John. He can lose John again, if it's necessary, and his own heart twinges at that, as if Mary shot him there instead of lower on his chest.

Silly John. Did he ever know? Did he need everyone to spell it out for him? The Woman, Moriarty, even Charles Augustus Magnussen. Because if there's one thing Magnussen managed to do that Moriarty didn't, it was to burn Sherlock. Burn his heart out of him. He got a bullet to the temple for that.

"Six months," he says to John, after John asks how long he'll be in Eastern Europe, working for MI6. "My brother estimates." He pauses. "He's never wrong."

There's a bit of a silence and Sherlock watches the realisation dawn on John's face. The last conversation. He'd said so earlier; John's only picking it up now that Sherlock might not return from this. And that's okay. That might be exactly what John Watson needs, what with a baby on the way and a whole new chapter in his life ahead of him. He doesn't need the splotches on the page that are Sherlock Holmes, marring the margins and lines he's tried to write.

"And then what?" asks John.

He's playing along, Sherlock knows. Just trying to keep a bit of optimism. He purses his lips for a moment and considers it. John Watson's sticking his head in the sand, refusing to believe that Sherlock Holmes may be going to his death.

"Who knows," he says, to keep it vague, and John inhales sharply at that, turning for a moment and looking around. Sherlock stares at him, committing each line on his head, each strand of grey-blonde hair, each new wrinkle to memory. He has never run his fingertips over them like Mary has, and he never will. And the thought of that makes his heart constrict, makes him look down for a moment because his eyes have taken in so much John that John has become his entire world.

Maybe he should tell him.

"John," he says, and John looks up at him again, lips puckered and eyes inquisitive. He remembers that expression and all the other expressions that John has ever made; he's committed them to various rooms in his mind palace. "There's something..." His heart picks up a little, and he pauses, "I should say – I meant to say, always – but I never have."

He can't bring himself to look into John's eyes.

"Since it's unlikely we'll ever meet again, I might as well say it now."

John says nothing to that, only stares at him, waiting for him to answer. John sees, but he doesn't observe. If he had observed, after all, it would've been plain as day. Anyone could see it if they truly looked, after all. The Woman did, and Moriarty did, and Magnussen did –

Oh, Magnussen definitely. And said it aloud, with visual proof – though, not in the words that Sherlock's mind has been using all this time.

Even when he thought he didn't believe in such things, Sherlock Holmes has loved John Watson with every beat of his borrowed heart, and everyone knows it – everyone, that is, except the one person who matters.

And even now, Sherlock can't say it. Can't remind himself of the fact that he is, in the end, just as predictable as anyone else. John's right; he's not a puzzle. He's obvious as daylight. His pressure points are on his sleeve.

"Sherlock is actually a girl's name." The words rush out of his lips before his mind can process it, and it's probably not what John's expecting because it certainly isn't what Sherlock was expecting. And John laughs at it, eyes and forehead crinkling in the way that Sherlock loves best.

"It's not," he points out.

"It's worth a try," Sherlock rebuts.

"We're not naming our daughter after you," John says, but he's smiling with that dimple on his right cheek, chuckling as if a heavy weight has been dropped from his shoulders. And that breaks Sherlock's heart all over again.

"Oh, I think it could work," he says, even though it's hard to breathe (and he's not sure if that's just him or residual effects of Mary's gunshot wound). The moment's passed, though; he has to leave, and John will remain here with Mary and their baby. There's no room for him in the picture anymore, and maybe some distance is all he needs to clear John from his mind and hollow out the fragments of his broken heart.

Even if the two-year hiatus hadn't been all that useful on that front.

He extends a hand. "To the best of times, John," he says. John's hand is warm in his, as it always has been; Sherlock cherishes the warmth a moment longer, clinging to the remnants after it's gone like a memory to be tucked away in the recesses of his mind, added to his collection of files dedicated to John Hamish Watson.

When the plane takes off, he watches the receding figures on the runway below. John and Mary, together. Happy. Safe. Because that's what matters in the end, isn't it?

Sherlock Holmes's pressure point might be John Watson, but John Watson's isn't Sherlock Holmes.

And that just goes to show the inevitability of human error.