Hello, everyone! Here we go, my first foray into the wonderful world of Johnlock. Please enjoy! (Mature rating for drug use, language, potentially triggering scenes, and eventual sex.)

Note: This entire story is pre-Reichenbach, and takes place between "The Hounds of Baskerville" and "The Reichenbach Fall" of Series 2.

"He's not like that. He doesn't feel things that way. I don't think."

"John, my brother has the brain of a scientist or a philosopher, yet he elects to be a detective. What might we deduce about his heart?"

"…I don't know."

oOo

Terra Incognita, Or: A Handbook for the Scientist in Love

I: Piezoelectricity

John stepped into the front room, kicking the door shut behind him and compulsively smoothing the lapels of his jacket for what seemed the thousandth time. "Well?" He took a deep breath, holding his arms out. "What do you think? Will she be impressed?" The lump on the couch shifted slightly.

"You've put two condoms in your wallet tonight," came the slightly muffled response from beneath the heavy blankets. "You tell me." John's arms slumped to his sides.

"You know, I really hate you sometimes," he seethed, annoyed and unable to keep from feeling slightly cheapened by the inference. But the lump only chuckled. "Can you at least bother to look?" urged John, tapping his foot impatiently on the floor. "Please? You know formal wear's much more your forte, and I'm taking Mary to a nice restaurant tonight and a show afterwards, so I want to look the part. Please, Sherlock? For me?" A pause, and then the lump shifted again, this time revealing a small sliver of face from out beneath the swaths of fabric, and one bright grey eye blinking as it adjusted to the light. John stood still, watching as it looked him up and down.

"You look fine." The three words were delivered quickly, and then the eye disappeared back into the sea of blankets.

John nodded, brushing off Sherlock's terseness with practiced ease. In truth he'd been hoping for something a bit more helpful, but he knew his flatmate well enough to read when the man was in a mood, and Sherlock's recent downswings had been so dreadfully black John supposed he was lucky he'd gotten any response at all. Perhaps, he mused, it had something to do with the fact that Christmas was now just a week away—Sherlock hated the holidays like the plague. He'd nearly run Mrs. Hudson out of the flat when she'd bustled in one morning two weeks prior with the same armful of decorations she'd helped them set up the year before, and then, minutes later, John himself when he'd come to the poor woman's defense. What ensued was a nearly twenty-minute long debate on the pros and cons of Christmas décor, around and around until John had simply caved under the sheer asininity of it all, followed by the irascible (and by that point unbearably victorious) Sherlock pointing the long-suffering landlady out the door, armful of decorations and all. She'd gone, but not before throwing John an apologetic glance.

"I'll just keep them downstairs for you boys in case you change your mind," she whispered to him, to which Sherlock lost no time in piping up, "We won't," and stepping forward to slam the door in her face. John bristled, following his flatmate as the detective stormed into the kitchen.

"What the hell was that, Sherlock?" The sounds of Mrs. Hudson struggling with the armful of decorations as she descended the stairs were painfully audible to both men, but Sherlock had seemed too preoccupied to notice. He was already elbows-deep in the disturbingly makeshift chemistry lab he'd erected upon their kitchen table, holding up one bottle of chemicals after another, inspecting their contents carefully. John's question, of course, went unanswered, though the doctor swore he could hear mutterings of "Illogical," "Senseless," and "Massive waste of time" under Sherlock's breath.

"You know, you didn't have a problem with decorations last year!" John said, pointing a condemning (though ultimately futile, as the man didn't even bother to look up to see it) finger in Sherlock's direction. "What's so different now?" There was genuine confusion buried in the question, but by that point Sherlock had either decided to ignore John or had tuned him out completely, for in response the detective simply readjusted his safety goggles and hunched closer over his current experiment, something involving human hair and fire and fluoroboric acid, and just the thought of what that was almost certainly doing to the kitchen sink John hadn't the mental fortitude to contemplate. Cursing lightly, the doctor threw his hands up in exasperation and then resigned to let the matter drop, for the time for discussion had clearly ended; Sherlock had gotten his way, and that, as the stubborn detective always made sure, was the end of it. The pattern was nothing new, but John still found it positively maddening, and with a scowl he snatched the morning newspaper from the side table and buried his nose deep in the headlines until his anger at last ebbed away amidst the rolling grey soup that was Britain's daily in's and out's.

It mightn't have been so bad, John thought. After all, it was just a passing squabble, a 'little domestic' as Mrs. Hudson would say, and besides, he was a grown man and wasn't about to be done in by anything as trivial as lack of fairy lights. The problem, once again, became Sherlock, and the way his moody anger only seemed to fester as the days rolled on. John was shocked the detective's fingers hadn't worn to the bone the way he sawed away at his violin night after night, and during the day, well, god help the jolly shopkeeper or inattentive pedestrian fate happened to toss into the warring Sherlock's path. Poisonous glares and some rather inappropriate deductions soon became commonplace, and John was forced to apologize so many times for his flatmate's berating strangers in the street that soon the words were rolling off his tongue practically by rote. However, the afternoon Sherlock went off on a hassled mother toting a shopping bag on one arm and a wailing child on the other, revealing in one fell swoop to everyone within earshot in the busy street corner that the diet she'd been on for weeks clearly wasn't working, as her husband was currently sleeping with the family's au pair, John decided that Sherlock had simply gone too far.

Now, glancing over at the small tree he'd set up near the fireplace, watching its little white lights blink on and off, the doctor's face broke into a small smile. The thing wasn't more than a couple feet tall, and tacky and cheap to boot, yet John found it oddly charming—and the fact that Sherlock had thrown a fit when he'd found it mixed in with the rest of the shopping the day after he'd reduced that poor mother to tears only added to the appeal. True to form, Sherlock had demanded John return the tree immediately, and even went so far as to attempt to bin the boxed decoration in its entirety when John refused. But John ripped the box from the detective's arms (it was all so pathetically childish but god help him if he wasn't going to stand his ground), arguing that he was certainly owed a tree at Christmastime if Sherlock was allowed to spray paint and shoot holes in the walls whenever he got bored, and besides—and here John summoned his most authoritative captain's voice—just because Sherlock didn't understand or feel sentiment himself didn't give him the right to stomp around London ruining the holiday for everyone else. They were keeping the tree, god dammit, for once they were going to do something John wanted to do, and if that pissed Sherlock off, well, Sherlock could just deal with it.

That final quip earned John two days' worth of Sherlock's silence and sour glares, but, thought John triumphantly, the tree survived, though forever after the detective refused to acknowledge its existence. And then, well—John's eyes darted up to the few strings of multi-colored lights tacked up around the windows. They'd been a gift from Mary, a joke, presented to him after he'd told her how his irritable flatmate despised the holiday season. John knew he'd been pressing his luck in putting them up, and indeed, he half-expected Sherlock's head to fall off when the man returned home one night to find them shining away, bathing the flat in dim shades of rainbow. "Common," the detective had spluttered hotly, fists clenching and unclenching at his sides as he stood frozen in the doorway, his face a mask of abject rage. "Juvenile." And John simply laughed and rolled his eyes and turned up the telly, leaving Sherlock to storm off to his room, slamming the door in his thunderous wake.

That had been four days ago. John wasn't sure if Sherlock had forgiven him for inundating the flat with Christmas cheer (though John and Mrs. Hudson had shared a good chuckle about it the day before), but if the detective hadn't yet he certainly wasn't going to do so anytime soon: the man had spent the majority of the day sprawled motionless on the couch beneath nearly every blanket in the flat. "Cold," he'd muttered to John that morning after emerging from his room with yawn and a scowl, whereupon he'd cranked the fireplace gas up to a level that could only be categorized as borderline pyromaniacal, gathered every piece of rectangular fabric at his disposal, and then promptly buried himself beneath them all. John, silently observing the action from behind the rim of a cup of tea, hadn't pressed for explanation. Yes, the icy gusts outside were frigid, but one didn't require a degree in psychology to infer that Sherlock's mood had very little to do with temperature. Beyond that rudimentary insight, however, the doctor found himself stranded against Sherlock's usual wall of mental impenetrability; the detective's sulks were a veritable force of nature, ten times as dangerous, nowhere near as predictable, and just about as enjoyable as your average hurricane.

If Sherlock wanted to be miserable, John figured, so be it.

"There's some chicken leftover here in the fridge, Sherlock," John called out, turning into the kitchen. "Just in case you feel like eating tonight. You should, you know—you haven't at all today, and you're not on a case so you have no excuse." He opened the cupboard for a plate, then rummaged through the drawers for a clean knife and fork and placed them all carefully by the microwave. "There's clean dishes here for you to use, so do try to make an effort, yeah? I'm not sure when I'll be back, but you can make yourself some tea in the morning if I'm not here—" He filled the kettle and fished a clean mug from the drying rack in the sink, setting the two together "—and there's oatmeal on the shelf if you feel up for it. Oh, and I think the milk's gone off, so check the expiration date if you want to use it, all right? Other than that, just don't blow up the flat while I'm gone, and be civil to Mrs. Hudson if she comes up—"

"John."

The doctor turned to find Sherlock standing in the kitchen doorway, inexplicably up from the sofa for the first time in hours. His body was cocooned in a heavy plaid duvet he'd dragged along with him from the couch, one corner draped atop his head and its opposite trailing loosely on the floor behind him. Frowning, John set down the bowl he'd been washing just in case Sherlock felt like breakfast in the morning. "Yes, Sherlock?"

"Don't."

John blinked, confused. "Don't what?" But Sherlock didn't answer. A look of consternation flit across his face, and for the briefest second his lips pressed together as though he were struggling with his words. A moment later, though, the look vanished, and the change in expression was so subtle John wondered if he'd imagined it completely.

"Don't wear your tie like that," said Sherlock.

"My tie?" John craned his neck downwards to look for errors. "Why? What's wrong with it?"

"That's a four-in-hand knot," said the detective, absently tossing a few stray locks of hair from his eyes and causing the duvet corner to bobble on his forehead. "If you're taking Mary (he uttered the name with particular scorn) somewhere nice, and you want to look the part (again, with particular scorn) you should use a Windsor Knot, or a half-Windsor at least."

"Don't mock me, Sherlock," warned John. "I know you don't like her, alright? I get it. I know. She knows. We all know. But that's not going to stop me dating her. It's not," he emphasized, as Sherlock pulled a face. He turned back to the sink and his scrubbing. "You know perfectly well what I meant when I asked you for advice—shirt and suit matching and all that—so don't get cheeky. Anyway, even if I wanted to, I haven't tied a Windsor since I was in the army, which I'm sure you're perfectly aware of as well. I don't even think I remember—"

"Then let me do it."

John stuttered to a halt. "...What?"

"I'll tie it for you. Come here."

The doctor frowned, casting suspicious eyes up at Sherlock. Generosity was rare from him; selflessness a word nearly missing from his lexicon. John had half a mind that Sherlock was still teasing. And yet this was the first kind thing his flatmate had offered to do for him in ages (and in the wake of their quarreling, John thought, nothing short of a miracle). So he set the half-rinsed bowl in the sink, drying his hands on a tea towel before crossing the kitchen to Sherlock. The detective's hands immediately emerged out from the folds of the duvet as he drew near, taking John's tie up in his long fingers and gently pulling the knot loose.

"I thought you didn't wear ties," John muttered, keeping his head turned down and to the side as Sherlock straightened the silk around his neck, expertly folding the ends over and then under, tugging them this way and that. "I've never seen you wear a tie."

"Doesn't mean I don't know how to tie them," Sherlock answered, his eyes focused on the finished knot as he slid it upwards and secured it at John's throat. "There." He gave it a final nudge. "A half-Windsor." And then, almost as an afterthought, he ran a pale finger down the length of the tie and buttoned John's jacket closed over it. John swallowed sheepishly, feeling the knot around his neck, and managed a smile. He didn't have to venture a look in the mirror to know it was perfectly executed.

"Thanks," he said, turning up to Sherlock.

Something flickered in the detective's eyes then, that same strange gleam, but once again it vanished almost before John had had time to suspect he'd seen it at all. And yet, John thought, he simply couldn't have imagined it twice in a row; no, it was something, something Sherlock was trying to tell him without words, and as their eyes lingered on one another just a beat too long John was sure he saw it again—There!—swimming right below the surface, but what was it, what, what, what—

"Your cab's here," Sherlock said suddenly, and no sooner had he spoken than the bell downstairs rang. As if on cue, his hands retracted back into the blanket and with a silent flourish he spun about, sweeping from the kitchen and falling back onto the couch with a put upon sigh. John bit his lip, wondering, but the bizarre moment had passed, and with a shrug he reached for his coat on the hook by the door.

"Try to remember to eat," he said over his shoulder. "I've got my mobile if you need me. If you need me, Sherlock," he added quickly. "You'll remember our conversation on the differences between needing and boredom."

"They do match, John."

The doctor paused halfway through the door, then turned around, poking his head back around the corner of the sitting room. "What was that?"

"Your suit and shirt," clarified the detective, propping himself up into a sitting position and peering at John from his nest upon the couch. "They do match."

"Oh." A small, preening grin tugged at John's lips. "Well, thank you, Sherlock."

Sherlock nodded, continuing to stare. In a way he'd told a half-truth, a lie by omission: John's outfit did match, but it also looked…it looked…Sherlock pursed his lips, trying to think of the proper word, and arrived at good. Yes, that was it. John looked good.

It was not the first time Sherlock had come to such a conclusion. The detective knew John didn't consider himself a very fashion-forward individual, and perhaps with good reason: Busy doctor, served overseas, spent his university nights holed up in labs and libraries with few distractions. Popular enough, social, amiable, but never posh. Confident but modest and never considered himself remarkably attractive. And yet in spite of all that, or perhaps because of it, John maintained a certain kind of awkward, nerdish charm (made all the more sincere, Sherlock mused, by the doctor's complete and total ignorance of it). After all, this was a man who owned a closet full of cable-knit jumpers and woolen vests, checked collared shirts and worn leather shoes, and John couldn't afford much better and didn't care to, even if it meant looking rather plain next to someone like Sherlock, who owned nothing but tailored suits and Armani brogues and refused all lesser alternatives. But Sherlock also knew from firsthand experience that John could clean up nicely when he wanted, and tonight, decked out in his best suit—a fine, dark grey wool—Sherlock couldn't help but acknowledge that John cut a surprisingly dashing figure, from his crisp white shirt and patterned tie right down to his argyle socks. Sexy, Sherlock thought, and the word took him by surprise, because he'd never really thought of anyone as being sexy before, even John. But that was it, better than good, and far more exact: sexy. Tonight, John Watson looked sexy.

Sherlock suppressed a shiver.

"You look…nice," he finally mumbled. "Very handsome." The words sounded clumsy on his lips, but John, fussing with his scarf in the doorway and still smiling that little prideful smile that was far too becoming than it had any right to be on his clear, open face, didn't seem to notice.

"Thanks, Sherlock," he said softly. "That really means a lot, coming from you."

Curious words, and even stranger sentiment behind them, and once again a pregnant pause bloomed between the two men, and once again they seemed on the cusp of breaching something very odd indeed. But, before either could break the silence, Mrs. Hudson was calling up from the ground level to tell John his cabbie was at the door, and the intrusion dissipated the moment completely. Startled back to normalcy, John blinked, then shrugged his coat on over his shoulders. "Coming, Mrs. Hudson!" he called after her, and with a last nod and wave to Sherlock (along with a final plea for him to eat something, anything), John disappeared down the stairs. Sherlock stared after him, deeply silent and bizarrely affected, and long after he heard the front door slam closed the detective could have sworn he could feel the sound of its shutting reverberating in the hollowness of his own chest cavity.

For a moment the flat was quiet save the intermittent crackling of the fire at the hearth coupled with that resonant echoing, and those few seconds that filled the space of John's departure quickly stretched into minutes, piling up one after the other, spilling onto the space of Sherlock's mind and multiplying upon contact until their combined load threatened to tip itself over into cavernous eternity—

And then, as though some great internal switch had been flipped, Sherlock was suddenly restless, practically itching to move.

He wanted to do a million things at once. He wanted a case; he wanted to chase a criminal through the streets of London, dark alleys and dank sewers and high above on rooftops, leaping from one to the next, feeling the wind on his face and the breathless thrill of cheating death with every jump. He wanted the adrenaline of the solution—that fantastic, ephemeral moment when all the evidence aligned and crystallized into a truth he alone could decipher—he, Sherlock Holmes, and no one else. He wanted Lestrade's congratulations and bumbling thanks, Donavan's spite and Anderson's jealousy, and the reporters and the papers and all their attention he so voraciously loved to hate, and he wanted John, good old dependable John, standing off on the sidelines, waiting for him in the corner with his hands in his pockets, smiling up at him, proud. And then Sherlock twitched, heart racing, eyes shining, overcome with something new. For in that instant he also wanted to leap from the couch and call after John, or run after him, hail a cab and track him down and grab a hold of John's coat and hold him, breathing in the scent of John's skin and shampoo and the musky cologne he only wore on special occasions like tonight. Sherlock wanted to scream. He wanted to shoot holes in the walls; he wanted to smash every object in the flat to pieces. He wanted to take all of John's girlfriends by their scrawny, simpering necks and strangle them one by one, then do the same of every woman in London, in the whole of England, and then John would have no choice but to take him out to dinner and a show afterwards, and wear his best suit for him and put cologne on for him…

…and put two condoms in his wallet for him…

"No!"

The word was out from Sherlock's lips almost as immediately as the thought was in his head. Springing from the couch as though he'd been badly shocked, the detective stumbled wildly to his feet, sending pillows and blankets flying in all directions and shaking his head in stunned disbelief. He couldn't understand why—why would he even think something so absolutely disgusting? Impossible. No. He was Sherlock Holmes, and he'd never wanted…that before, not ever. Closing his eyes, he took a deep breath, working to stabilize his racing mind. Be rational, he thought. Remember who you are. Calm down.

Calm down.

Calm. Down.

And then, it happened.

It happened very quickly. Much, much later, years and years and decades later, Sherlock would think that he must have somehow sensed its approach, for there was no other way to explain in that moment his set jaw, and his hands clenching the edge of the duvet he'd pulled with him, his back and shoulders tensing in anticipation as though a great storm was about to break right before his eyes.

It did, and it happened very quickly. He did not, could not, stop it coming.

In that moment, the skeletal facts: He was Sherlock Holmes, consulting detective, resident of London, England, and he was exactly thirty-four years, eleven months, and eighteen days old. He had exactly two parents, deceased, exactly one brother, tragically not-deceased, and exactly one John Watson, his friend, and until that moment nothing more than just that. In regards to everything that came after, the tumult of change, and the Pandora's Box of strife and charged brilliance that was unleashed upon him and left to peter out in fits and starts from that point until his dying day, Sherlock, a man devoted to the sanctity of logic, never measured anything as relevant and as categorically true as these three simple and therefore most critical facts gained in that instant, the moment in which his life changed irrevocably and forever:

That the paradigm shift, the only one he ever underwent in the course of his life, happened, that it happened at that very moment, and that it happened very quickly.

The thought of John snapped back into Sherlock's brain.

It lit up his neurons like ignited magnesium—John, smiling, charming, dressed in his dark fitted suit, and he was standing in the kitchen and asking Sherlock to tie his tie again, except that this time Sherlock didn't, this time Sherlock gathered the silk in his hands and pulled John into him, hard, rough, the way he'd wanted to just minutes before—

"No!"

Sherlock stumbled, dropping the duvet and reaching out a hand to steady himself against a nearby wall, pulling at his hair in distress. Where had that image come from? Why was it suddenly filling his brain, pushing all other thoughts aside? And why couldn't he make it go away? "Stop it," he murmured, though the edge in his breathy, panicked voice made his heart race all the faster. "Stop it, stop it, stop it." But Sherlock could feel his body betraying him even as he spoke, and his pleas dissolved into a heated whimper as an uncomfortable flush ran through him, followed closely (to his complete dismay) by a ball of fuzzy warmth that welled in his stomach before working its way down and pooling between his legs.

"Nngh…" Sherlock's tongue rolled uselessly behind his teeth, and he found the garbled nonsense pouring from his mouth at once humiliating and frightful. Grimacing at his own incompetence, the detective pressed his forehead into the wall, trying to will the image of John away, but it only intensified and shifted in form: Now, bright morning light was pouring through the front room windows, and John was freshly showered and sitting in his favorite chair. He was reading the newspaper like always, absentmindedly humming some tone-deaf tune like always, but this time when Sherlock walked past the doctor reached out and grabbed his hand, casting the paper aside and pulling Sherlock into his lap before nuzzling into the small of his back with a soft, throaty growl. Panting into the wallpaper, the detective could almost feel the way John's strong soldier hands would hold him, slipping under his cotton shirt and running up his chest to caress his nipples lovingly, and how, if Sherlock would arch his back and position himself just so, he'd be able to feel John's burgeoning erection through the seat of his trousers—

Sherlock moaned, gasping against the wall as a particularly violent sensation he didn't understand bled through his extremities. He could feel his penis pressing against his pants now, begging to be touched, and it took the detective summoning every last modicum of restraint he had to keep from plunging his hands down to his crotch, though to do what he wasn't exactly sure. And yet Friction! his brain screamed, so powerfully that Sherlock couldn't keep from and glancing down at the tented fabric and the little spot of wetness beginning to spread at its peak. A strangled gasp caught in his throat. There was something so…so unbelievably stimulating about that sight, of himself so aroused, and then, quite without meaning to and almost certainly guided by some latent instinct that only made him hate his body further, Sherlock snapped his spine forward and ground his hips against the wall with a heated cry. The pressure sent something electric zipping before his eyes, a wild tangle of pleasure and warmth, and before Sherlock knew what he was doing his body repeated the motion, rutting against the wall once more in a long, hard drag that had his entire frame tensing in primal satisfaction.

A third thrust, and Sherlock found himself sinking weak-kneed to the floor, groaning piteously and detesting the way his whole body felt hot and sticky and stifled by everything around him. He yearned desperately to open a window and hurl himself into the snowdrifts heaped on the pavement below, or, better yet, to take John's Browning and put a bullet through his head, ending this undignified torture. But he couldn't; all Sherlock could do, it seemed, was pant and writhe upon the floorboards and think of John, and the ruthless fantasy bubbled back up from the depths of his psyche and shifted again: This time, John was pinned beneath him, naked, red-faced, moaning, his legs wrapped tightly around Sherlock's waist, and Sherlock was naked too, sweat dripping from his temples as he dug his nails into the twisted flesh of John's Afghanistan scar and thrust shamelessly into him, again and again and again. They were having sex on Mycroft's desk, no, they were having sex in the sitting room at Buckingham Palace, and suddenly Mycroft was there, horrified and furious, and all Sherlock did was laugh in his brother's face and ram into John harder, making the doctor throw his head back and scream Sherlock! Sherlock! Sherlock! because Sherlock wanted Mycroft to see, he wanted Mycroft to have perfect, incontrovertible proof that sex didn't alarm him and that he wasn't a virgin, that he knew how it worked and knew how to love someone and be loved back. And then, staring his brother straight in the eye, Sherlock thrust deep into John a final time, and John screamed and came and Sherlock did too, and then they kissed, breathing each other in and wrapped up in such perfect, ferocious ecstasy that everything else fell away, Mycroft and Buckingham Palace and everything, and all that was left was John and Sherlock, Sherlock and John, together—

"John!"

Sherlock screamed, and his back arched up off the floor as orgasm tore through his body, flooding him completely. It was wonderful, terrible, and Sherlock hated every second of it, because even as the throes of pleasure ravaged him he was dreadfully cognizant of a loud boom echoing through his mind's eye as every entrance to his mind palace slammed shut at once, leaving him petrified and stranded and on the outside. It was instantaneous severance, deep, visceral, and highly disturbing, for suddenly, for the first time in his life, Sherlock was without information: no thoughts, no reason, no weapon to bear against the sensations devouring him, and the flesh and blood fingers digging into the floorboards as the last of his ejaculate streamed into his pants mirrored metaphorical fingers as they scrabbled desperately at the bolted doors of the great mental construct. He needed to get back inside, had to, but was impossible to think, all he could do was feel, and that was the most unbearable thing of all, how very much he was feeling at this moment, and he was losing himself in it, surely, because a Sherlock who couldn't think wasn't Sherlock at all—

A final whimper tumbled from his lips, and then he collapsed, breathless, disoriented, and weak. Blinking, barely half-aware of his actions, he rolled to his side and curled his body into a tight ball, trembling uncontrollably and trying to ignore the new and unpleasant wetness in his pants.

The room appeared to spin above him. Christmas LEDs chased after incandescent lamplight, mingling with the dancing shadows cast off from the fire, and somewhere, far in the distance, Sherlock heard the groan of doors on massive, old-world hinges as his mind palace swung open once again. Relieved, he dragged himself back inside only to immediately stop short, for the cool stones beneath him now seemed somehow foreign, the vaulted arches high above and the winding stairs and mantled doors all subtly shifted in pitch, shape, and timbre. It was as though he were encountering his mind palace through Carroll's looking-glass, but try as he might he couldn't drop the shade, and slowly, as Sherlock tried door after door, tearing at an increasingly frantic pace through an endless stream of unfamiliar halls and passageways, the detective realized at last with a kind of stuttering, seizing terror that he was the something different, the thing that had changed. He was the thing that no longer fit.

The paradigm shift was done.

That this was not truly an end but a mere change in direction was insight gained only in retrospect. At the time, as it was, Sherlock felt only confusion, a terrific sense of loss coupled with the grossly terrifying realization that nothing like this had never happened to him before. To think that he, he, had just…no, he didn't even want to think the word, it was so appalling. It was sick. But it had escalated so quickly, and he'd been so powerless once it had begun! Surely, thought Sherlock, I'm not to blame. And yet this thing, this act, it clung to him still, was him, and refused to be broken down, analyzed or understood. He swallowed thickly, gripping his arms to his chest. It seemed he'd dealt himself the ultimate blow: he'd collected an experience so wholly new and unlike anything else he'd ever known that nothing in the whole of his mind palace could serve adequate comparison, something so completely in the realm of feeling and base instinct that it defied logic and any attempt to cobble it into a measurable entity. Terrible. Unforgivable. For god's sake, he was lying crumpled on the floor in a sorry, shivering heap! How could anyone ever do this willingly? How? The question repeated ad nauseam in Sherlock's head, spiteful and tinged with panic. Arousal. Orgasm. How could anyone ever find such a horrid loss of control enjoyable? Had…had he found it enjoyable?

What's wrong with me?

Sherlock's throat burned, and now it was that question rolling around in his skull, growing larger and louder until the shame of it pried a heaving sob from his throat. Determined not to break down, the detective curled tighter, and suddenly felt overwhelmingly exposed—he wanted John, yes, John would know what to do; John would be able to explain to him and clean him up and set him right again, and then Sherlock would delete this entire experience, and then—the detective fidgeted, grappling for the familiar—and then he and John could have tea and watch crap telly and fight about who would do the washing up this time around and things would go back to the way they were supposed to be. To normal.

But no, impossible, because Sherlock didn't want John to see him like this. He didn't want John to see him ever again.

—It's his first stint in detox, and he's lying in a bed wrapped in rough, bleach-smelling sheets—

And at that moment a sudden wave of nausea swept over Sherlock; scrabbling from the floor, the detective barely made it to the bathroom in time to vomit up the contents of his stomach into the toilet. He hadn't eaten in nearly a day and so it wasn't much more than bile, but it was enough to sear the back of his throat and force a cold sweat from his pores, and when he was finished he coughed, gagging, trying to spit what remained of the noxious acid from his mouth. Disgusting, he thought, clinging weakly to the porcelain bowl. Absolutely repellent. And he vomited a second time.

He binned his soiled pants as soon as he regained the energy to stand. Using a towel, he next wiped his lower half clean as best he could manage, then tossed the cloth away as well. After making a mental note to burn the incriminating evidence as soon and as discretely as possible, Sherlock turned to the sink and washed his hands…then washed them again, and then a third time, and then a fourth, and as the detective was busy scraping nonexistent detritus out from beneath his left thumbnail, a part of him frantically wondered if this was his OCD resurfacing, rearing its ugly head for the first time since adolescence, but he couldn't help it, he couldn't stop; his hands simply weren't getting clean.

But when Sherlock caught his refection in the mirror, he froze.

Pallid skin glistening with a sour sheen. Mussed curls sticking unattractively to the sides of an anxious, ashen face. A t-shirt, damp, clinging to his torso and making him itch, and beneath that, nothing, save a dark dense patch and his member hanging limply between his legs. Sherlock gripped the counter, unable to tear his eyes away from the nervous wreck staring back at him through the glass. Trembling body. Weak knees. Eyes wide and bright and filled with fear.

With fear.

Emotion.

Look at me. I'm afraid, John. Afraid. Sherlock's own voice rumbled back through the past, mocking him. Interesting, yes? Emotions…the grit on the lens, the fly in the ointment—

—It's his first stint in detox, and he's lying in a bed wrapped in rough, bleach-smelling sheets—

Sherlock didn't remember striking the mirror. He must've, though, and several times, because suddenly it was shattered and the sound of breaking glass was in the detective's ears and silver shards were falling into the sink, and then there was red, red drops on white porcelain and trails of it running down his hand—he'd sliced his knuckles open on the glass, yes, that's what he'd done. And it hurt, oh god, it stung terribly, but with half the mirror missing Sherlock couldn't see his reflection any longer, and that was a good, good thing.

Now he was free to do what he wanted, and nobody would be able to watch.

Still breathing heavily, Sherlock shut the water off. His movements were slow and stiff, and as he turned from the sink blood dripped from his fingertips onto the floor, smearing brightly beneath his leaden feet. His fingers left a lurid welt of red glistening on the plastic switch when he reached up to shut off the light.

John. John will be upset with the mess—

Sherlock paused in the doorway. For a moment he almost turned. For a moment he was filled with an uncharacteristically domestic impulse, a desire to fix what he'd broken: To clean and wrap his hand, to sweep the glass from the floor and sink, to mop the blood and disinfect the surfaces. Then John wouldn't be forced to do it himself when he returned. Then John wouldn't be mad. Then—and a small, obscenely joyous kernel of hope sprouted in Sherlock's chest at the very thought—then John might even be grateful; John would see Sherlock was thinking of him, trying to do something nice. For him.

But no, another, harsher part of the detective interrupted, and darkness clamped down on the fledgling mote of hope and squashed it into smoke, don't be daft; clean this up now, you great idiot, and John won't know you've done anything at all. Whatever message you're trying to send—The message is, a small, barely audible voice cried out, I'm trying—John won't get it. It's pathetic, and you've done enough damage already. Sherlock sighed as the desire drained away. Dull relief crept over him in its place, for the urge, however commendable, had felt misplaced, like a square peg jammed in a round hole.

Sherlock released a breath, something between a sigh and a sob.

And yet there was something sickly in that specific shade of comfort, something that left an unpalatable and uncomfortably familiar taste lodged in the back of his throat. The detective grunted weakly, shutting his eyes against it even as he felt it overrun his senses like thick fog. Pressing in, it mixed with the nighttime noise out on Baker Street and a low, resonant whisper that warned, very softly, No, don't go back there, don't be that person again. Then there was a distant siren, Sherlock's own breath rushing in his ears, coalescing together to say, It's okay, sexual arousal is just biology, and biology is science, and then a motorbike tearing along pavement in a way that urged, Don't be afraid! John is a doctor, John is your friend; John would understand! And then, beneath it all, the heated thudding in his chest beginning to wonder, awestruck with sudden possibility (and there was that golden kernel of hope again, rising like a phoenix from the ashes), John might even be flattered, John might even blush, John might even—

—might even—

—might even want—

But then, in an event of cosmic timing as perfectly cinematic as it was perfectly cruel, someone's too-loud television erupted with a roar of laughter from somewhere in the building. It was just sitcom laugh track bleeding through thin walls, but it was enough to collapse Sherlock's fragile house of cards on the spot, and all the detective could think in that moment was what a colossal fool he was acting, and then another peal of laughter echoed through his ears and his heart clenched painfully and the urge to climb out of and away from his mind had never felt greater. He couldn't bear the weight of himself any longer. No! No! No! No! screamed the clunking engine of a passing car, but too late—Sherlock detached, and the No! No! No! was just a clunking engine once more, and in that instant Sherlock became beyond everything, everything except the very next thing he was about to do—one call, maybe two—and the small, hated object stashed beneath the loose floorboard in the back of his bedroom closet, and the way it had pulled him back into its gravitational orbit at last.

Like a planet going round a star, his brain chimed stupidly, offering up the comparison in meager apology. Like a comet, thrust out deep into space along the curve of its elliptical but always coming back, never quite able to break free. But Sherlock refused to be lampooned, not by his own brain, and in spiteful retribution he furiously deleted everything he knew about planets and solar systems and comets and stars so many times over no astronomer alive or dead could ever hope to put the knowledge back.

It took just a few seconds; his face didn't even twitch with the effort and his hand still rested idly on the handle of the bathroom door. Drip, drip, drip, went the thin flow of blood from his fingers to the ground. Sherlock did not clean it up. He took a jerky step forward and closed the door quietly behind him.