A/N One away from completion, and a few away from 600 reviews.

Thanks to sparrowismyhummingbird, 666BloodyHell666, Rain Hamish Holmes, Starlight05, Song of Grey Lemons, Natalie Nallareet, johnsarmylady, ThisDayWillPass, and especially starrysummernights

Disclaimer I don't own Sherlock or any associated characters, events, etc.

XCIX. Solitude

Sherlock gets lonely, sometimes.

He never lets anyone know. As a matter of fact, he manages to convince them that he doesn't even notice his solitude—on occasion, that's true; but it's much rarer than he leads everyone to believe. It's because he doesn't want them to know, he supposes. Doesn't want them to know that he's much more sensitive than he's ever implied. Doesn't want himself to know, even.

After all, it didn't always used to be like this. And, if he's honest with himself, he can pinpoint exactly what prompted things to change: the arrival of his flatmate. Of John.

He doesn't like it when John leaves.

And, frustratingly, John leaves all too often. Whether he's headed to the store or New Zealand, it seems that he's gone with upsetting frequency. Sherlock feigns disinterest in his troublesomely common departures, but isn't quite sure why—as a matter of fact, it frustrates him sometimes, the fact that he can't just bring himself to say that he doesn't want John to leave.

Don't. Stay here this time. It's quiet without you, and I hate it.

But he can't say that. He never could, because it exposes weakness, stupid, absurd vulnerability. One of the many things that he's supposed to be immune to.

Like love. He's not supposed to feel that, by his own ruling.

Not love, and not loneliness, but both of those are suddenly prevalent in his life, hiding around every corner. And he tries not to think about them, because they both hurt, both burn.

Burn the heart out of you. That's what Moriarty said, at the pool.

And Sherlock's coming to realize, despite himself, that perhaps such a thing, burning the heart out of him, would be all too dreadfully easy. He's sensitive. He's sensitive, and it's all because of John.

And maybe, just maybe, that's part of why he hates the loneliness—fear. Not fear for himself, of course not (though that would be much more logical, much simpler and easier to deal with). No, he fears for John, can't help but worry every time he's out of his sight, because Moriarty's out there, too, out there in the world, and he won't hesitate before doing something to John. Harming him. He has before, took him at the pool, and Sherlock can't bear for that to happen again. Can't risk that emptiness in his stomach, that hollow horror that was undoubtedly the worst sensation he'd ever felt in all the years of his life.

And so he exhales, a tiny breath of relief, every time that John walks in the door. The doctor never notices, and that's good; Sherlock wouldn't expect him to, and certainly wouldn't want him to. He's glad that his concern goes unnoted. Because if anyone else knew, surely Moriarty would find out eventually. And then he would be destroyed.