John is pulled out of a deep sleep by shouting from downstairs. He's out of bed and half-running, half-falling down the stairs before he's even entirely awake, nightmarish scenarios of backup backup assassins coming after Sherlock running through his head.
He finds Sherlock on the floor of the library, wide-eyed, panting, and tangled in his blanket at the foot of the couch. He's not thrashing or trying to escape; he's just... lying there and staring blankly at the floor, seemingly exhausted.
John knows that feeling far too well.
Rustling his wings so Sherlock knows he's there, John approaches slowly and carefully. He stops moving when Sherlock's gaze flicks upward to meet his, but he's by the detective's side in a heartbeat when one large, elegant hand extricates itself from the blanket and reaches for John. Up close, John can smell the bitter, salty tang of tears and fear-sweat; it seems out of place set against Sherlock's natural scent. "All right, then. Come on, you, up you get. The floor's no place for recovering from a terror, I should know." When Sherlock obeys almost automatically, John feels a twinge of real worry. He's not sure he wants to know what it would take to reduce such a ferocious intellect to numb compliance, but it can't be anything good.
Sherlock reaches blindly when John moves away from his hand to readjust the blanket. "Don't go. Don't go, John, don't go," he whispers, almost childlike.
John abandons personal space for protective instinct and climbs onto the couch as well, folding one wing over the detective like a feathery blanket as he tucks himself into a too-skinny side. Sherlock curls into him almost immediately, burying face and hands into the thick fur and downy feathers of John's side.
Quiet reigns for a long time as Sherlock's breathing and heart rate slowly come back down to normal. When his hands finally loosen their grip on his fur, John turns and presses the tip of his nose to the top of Sherlock's head. "Tell me how you did it, Sherlock." The 'amaze me' goes unspoken but understood; John's tone is solicitous and warm. "Tell me where you've been."
It's another long stretch of silence before Sherlock begins, but John is patient. He knows how it can take time to dredge up the will to tell the tale, to make oneself vulnerable by exposing the cause of the pain, the anxiety, and the nightmares.
Apparently Sherlock had been expecting an escalation for some time; the pool would have been the final confrontation had Moriarty not been distracted by the phone call. As it turns out, the call had been from Irene Adler, whose information had much more potential to cause widespread chaos and scandal. With chaos and scandal came still more opportunities for Moriarty to gain influence over those his machinations had made vulnerable, and with influence over the powerful came more opportunities to sow yet more chaos and scandal.
"An ugly spiral," John comments. "Why did he do it, anyway?"
"Because he could." Sherlock replies simply. "Because he fancied himself some sort of god. He played with people like a child with a magnifying lens and an anthill. He dabbled in trafficking, bribery, and Ponzi schemes because more money would buy him a better magnifying glass with which to burn his playthings. He then discovered that he could manipulate the ants into doing his will, and that blossomed into a whole new game to play—give an ant a glass of his own and whisper in his ear, turning him against his fellows."
The full-body shudder that rattles John's feathers is entirely involuntary. "Christ," he whispers. "And he fixated on you because you turned a lens on him?"
"No. He fixated on me because he saw another boy with a lens."
The growl that escapes John is also entirely involuntary. "Bullshit!" he cries, on his feet and standing over Sherlock in the blink of an eye. "You're not like him! I won't believe it!"
Sherlock rolls his eyes and sits up, forcing John to back off. "John. I said he saw another boy with a lens. I did not say that I was using the lens in the same fashion. Frying ants to make oneself feel clever is pedestrian and boring; anyone can do it. Observing the ants objectively and discerning the purposes and processes behind the hive's activity is entirely another story." He shakes his heads and sneers. "Enough with the metaphor. Killing people, or even manipulating them to kill each other, is far too easy. Achieving any goal is too easy when one operates outside of the rules. Real challenges involve limits, taboos, and rules. Laws. I could easily become the next Moriarty if I so chose, but it would be dull, John, unconscionably dull. All that time and effort spent on what essentially amounts to an overcomplicated wank!"
John is too busy giggling like an idiot to bother with being a bit worried by Sherlock's reasons for not pursuing crime. "And here I thought you found laws annoying and pointless," he manages to get out in between giggles. "Overcomplicated wank! He'd have shot you for that on the spot."
Sherlock sniffs. "Laws are irritating but necessary. You see, John, most people are too stupid to be allowed to think they have any sort of autonomy. As for myself, laws provide a challenge; if I must break or bend one, it may only be bent or broken if it directly assists in providing a solution to a case that I could not solve otherwise. I admit that I have been forced to break far too many over the past three years, but some goals must be achieved at all costs."
John thinks of the cabbie and nods; laws come second when protecting someone for just reasons. He thinks of Mrs Hudson and Lestrade and the last three years, weighs his sadness against Sherlock's lonely crusade and the motivations behind it. He thinks about deceptions—Sherlock's faked death, Mycroft's silence about it. He thinks about Mycroft's bizarre, fang-filled smile and what it might mean for the detective, a man so bound in science that his keenly observant mind completely failed to put together the tells that marked John as something not quite human.
For the time being, he sets all those thoughts and questions aside and leans into Sherlock heavily, curling his wing around the detective's shoulders. There would be plenty of time to wade through ethics and to interrogate Mycroft later. "I'm right pissed that you lied to me, Sherlock," John says softly, "and if you do it again, I swear to God I'll leave and never come back, but... thank you. Thank you for doing that for us. For me." He smiles when the detective's head tilts to rest against John's. "I'm glad you're home. Now, carry on with the tale. Tell me everything."
