"John, listen, the evidence doesn't suggest anything of the sort. For the poison to be injected... she would have had to be close," Sherlock purses his lips so hard John's afraid they'll fuse together. The blood drains from then and they are pale white on his face. "Very," he says the word slowly, deliberately, "Close."

He says the words as thought to imply that the meeting would have had to have been more intimate than it could have been.

Than it should have been.

The facts are thus: toxin of questionable origin was injected into the victim's bloodstream (the victim's name is Nathan Chesterfield; Sherlock has not bothered to learn this) supposedly by the suspect in custody.

Stacey Tibbets, soon to be sister-in-law of the deceased; Sherlock has not bothered to learn this information, either. "What do their names matter to me, John?"

The victim had dropped dead en route to a taxi that was supposed to take him back to his flat in St. John's Wood. Mr. Chesterfield had left the ballroom in which a reception for the Elton John AIDS Foundation was taking place and had taken the time to call for the cab and to retrieve his coat from the check. He had asked one of the attendants to alert him when his cab arrived. He had, if the evidence was to be trusted, absolutely no reason to believe he would not make his cab.

He had specifically called for the cab, hadn't gone to fetch one on the main fairway as most people would do. He had a specific exit time in mind; there was an exit plan.

What he'd done between the time he had left the attendant and returned to the ball was what was in question. The single missing slide in the collection. The unpredictability of human action, there was no accounting for it.

Sherlock's eye dart back and forth across the sitting room before he stands abruptly, walking to the desk to ruffle through papers. It's going on the third day that Sherlock has been grasping at straws. There's a feeling about this case, something that nags at John, that begs at him to open his eyes and see. There's the lingering feeling that they're missing something that's so blindingly obvious that they've ruled it out without even considering it.

Sherlock does this often; his mind makes long, magnificent leaps and bounds that John can't even imagine making. However, in doing so, he regularly tends to overlook the obvious. He takes giant strides over the mundane, the minutiae of facts.

"Sherlock," John mumbles, the realization coming forth from nothing. It stretches, uncoils in the back of John's mind and presents itself slowly, languidly. The knowledge washes over him; John straightens his spine.

Sherlock does not turn, does not pause in his pacing. It would be fascinating to watch-as it always is-but John is so certain, can feel the truth gnawing at the base of his skull...

It's times like this that John finds his flatmate the most infuriating. Especially when he's sure that he has information that would be conducive to solving the case. John watches him make the circuit of the room a few times before he interjects once more, voice wavering with something bordering on anger. "Sherlock!"

He pauses, halfway to the couch, leaves his hands intertwined in his hair and turns towards John. Jaw set, eyes blazing, he shouts, "What!"

"The injection point was just to the left of the nape of the neck," John rationalizes it with his words and though it's not a question, Sherlock responds as though it is.

His hands untangle from his hair and he takes a single, near-menacing step towards John. "Yes, John, yes, we know that, we've known that for days. If you're not going to add anything to the-"

"They were dancing Sherlock," John exclaims, hands in the air. "They were dancing, before his cab came, he went back in to have one last dance and..."

"What?"

"It was..." John doesn't know how to articulate this to make Sherlock understand. The compulsion, the emotions that must have been coursing through the victim's veins. To send him back into the ballroom, to seek out his brother's fiance and dance with her. He doesn't know of a way to spell it out, really. "It was a last hurrah, a..."

"If he was in love with her why not have a clandestine affair why not... take what he could get? There's no evidence to suggest they were ever in a relationship, there was nothing there... so there's the one... dance, if there was a dance and what-" Sherlock glances ferociously around the room before settling his gaze back on John. "I hardly think one dance would be enough to risk his familial relationship over."

It's all getting to his head, three days without sleep, simultaneously working two cases; he's snappish, slightly erratic. John needs to find a way in which to calm his nerves, keep him in control until these cases are settled. Then he'll force Sherlock to take a day, take a day to walk through the park, take a nap, anything.

"Oh?" John's voice is even, but it sets Sherlock on edge.

"Generally speaking," Sherlock snarls; they'll not bring Mycroft into this discussion. Mycroft is an outlier.

"God, you're... how can you be this brilliant and this obtuse? He was in love with her Sherlock and she knew it and..."

"Doesn't explain the dancing," Sherlock deadpans and is back to pacing.

Jesus christ, this is infuriating. Absolutely bloody maddening. For a brief moment, John somehow understands Sherlock's own frustrations when he cannot pick up a thread of thought.

"Does it have to? As long as we believe it happened and it makes sense in the course of events, does it really have to be explained?" John hopes this will suffice but knows inherently that it will not. Because he knows it's true. They danced and she killed him.

Sherlock doesn't understand the mere act of dancing, doesn't understand why it people would engage in such a mundane activity.

Sex, sex he understands. He understands relationships even if he's never been in one. But this, this simple human act, he does not.

"Of course it has to be explained. These has to be a reason, they could have easily taken a hotel room, why would-"

John has balled his hands into fists, cannot take it anymore. If there were only some way of transplanting his knowledge and understanding into Sherlock's head... "Honestly, have you ever danced with someone that you-"

"No," Sherlock bites it out, turns on his heel, and pads into the kitchen.

"No you haven't danced or no you haven't... hold on, hold on, honestly?" John looms in the entryway and watches as Sherlock seats himself at the tiny kitchen table and hunkers down over a microscope. John takes a moment to admire the long line of his neck, try and juxtapose the milky skin again the utter blackness of Sherlock's shirt.

"Honestly?" John repeats again, aghast. He leans into the frame, settling in to watch, to loom, to impress upon Sherlock that he knows something Sherlock doesn't know.

"It's just moving your body to music; it's not a mating ritual. It's simply ritual, boring, human ritual." Sherlock glances over at John, sharply. "Boring," he emphasizes.

"Says the man who's never danced before," John says snarkily and glances up at the ceiling. He's aware that Sherlock's pervasive brilliant had been cause for him to miss out on some of the more common life experiences. He was aware, for instance, that Sherlock had never been present at a wedding, had never attended a funeral, had never held anyone's hand as he strolled through Regent's Park. Thus, he was shocked at how surprised and truly sad he was at the notion that Sherlock had never once in his life had a waltz with anyone.

"John, music is simply-"

"Oh no, don't try and, and rationalize music. Don't break it down into components because I will beat you over the head with your violin and don't for a second think that we're not going to discuss the fact that... you've never danced before?" There's a small smile on John's lips and he knows, just knows the way Sherlock grinds his teeth ever so that it's getting to him.

"Is this going to be-"

John takes particular glee in cutting him off on this occasion. "Oh, it most certainly is going to be a thing. Is it possible, is there a remote chance that I'm aware of something you aren't?"

Sherlock snorts as though that's impossible but, well...

"With the proper person," John unfolds his arms and stands from his leaning position against the frame, "Dancing can be more intimate than sex. With the wrong person, that is to say... your father, your sister, your best friend, even then it's a wonderful, shared moment. It's not, it, it's..."

Sherlock blinks at him, mouth twisting up in something very near disdain. But he's listening, intently.

"It's all a playground for 'something more', Sherlock. You don't engage in a dance with someone that you don't have some sort of feelings for."

Sherlock's composure falters for a moment and he flinches.

"I can't," and John smiles in spite of himself. "I can't explain it really. There's a bubble, it's as though you're in a bubble and... no, that's not it either, I..."

John starts towards the sitting room and unearths his laptop from a mound of paper. He turns it on and Sherlock waits and watches as John boots it up, fiddles with the touchpad, clicks on a few things and then stands.

John stands straight, in the living room, orders, "Come here."

Sherlock rolls his eyes quickly, makes to look back into the microscope before snapping his head back up. "There's work to be done, John."

"You're the one who loves to experiment, come here." John motions at him with his hands for him to just get up already and with a roll of his eyes and a brash, calculated movement Sherlock stands and lopes up to John.

The flat is quiet, more so than normal, possibly due to the fact that snow is falling steadily outside, the flakes somehow dulling the sounds of the world happening on the streets below them. The fire has warmed the room so much so that Sherlock has rolled up the sleeves on his oxford and John has opted for a starchy black tee-shirt in lieu of his usual jumper.

The taller man blinks and takes care to look completely pained. "On with it, yes?" He asks, shrugs and huffs and acts fully and totally as though he's being massively inconvenienced by being asked only to stand thus far. Like a petulant child, asked to come in from the playground.

It is John's turn to roll his eyes and huff and he leans over to the computer and taps the space bar. The music takes a moment but when it spills from the speakers it's slow and jazzy, a song John can imagine Nathan and Stacy having danced to.

He clears his throat and hold out a hand. "Alright, now your left hand in my right, there, and... no," Sherlock's hand is limp, feels almost perfectly so and John clenches around the thinner palm. "Please, Sherlock, just," Sherlock grips, "Yes, thank you."

The music swells a bit, but they're not ready. "Let's do this proper, so that we only have to do it once?" John grits but enjoys having Sherlock this close, so enjoys being able to hold his hand and guide him. "Right, now," John twines his arm underneath Sherlock's, lays it carefully around the curve of his ribs and settles, for a sweet second cataloguing the temperature of his skin beneath the fabric.

"Your hand, goes," and without John's words Sherlock lifts his arm, rests his hand purposefully against John's bicep. The height differential makes it slightly awkward, but John adjusts his arm around Sherlock's side and Sherlock adjusts likewise. They work around one another, find the best fit. Somehow, it works.

"Yes," John speaks, surprised, pleasantly so. He closes his eyes for a moment, takes a reprieve to feel the man in his arms. Sherlock is still tense, but he's relaxed enough to let John fiddle with their stance and he makes absolutely no objection when John (giving in, dear god, he's letting himself give in) takes a step closer and their chests press together just so.

There's a shift, something tacit and so vibrantly real that John swears that the planet has rippled it's skin. He feels it, down to his marrow. Sherlock sucks in a quick little breath; it whistles through his teeth and John tilts his chin to glance up at his eyes. "All right?" John asks, knows the answer is "No, absolutely fucking not, all right" because he's so certain that Sherlock can see the gooseflesh that has caressed every inch of exposed skin.

It's not alright because Sherlock says nothing, simply sinks his incisors into his bottom lip and actually bites down.

"Sherlock," John tries, but his voice wavers.

There's a hint of a smile, just the side of Sherlock's mouth flutters. "Yes?"

"I'm going to..." The words escaping and John's mouth dries; they remain silent as the song slides swiftly into another slow, jazzy number.

Sherlock leans in a bit, sets his jaw and feigns for all he's worth that there is nothing happening at the moment at all. "Lead away," and yet his voice too wavers and John has to swallow hard several times before he can manage to make the synapses fire so that his feet are able to shift.

It's amazing that they're this quiet, this paced. What's the most brilliant, the most stunning thing about all of this is that Sherlock isn't trying to compartmentalize what's happening; he isn't carefully deconstructing their actions, or speaking revelations about how this relates to the case. He is perfectly quiet and uncharacteristically pliant in John's hands.

He's allowing John to lead him, giving him the opportunity to take control.

John sighs and shifts closer to his partner, can feel the heat radiating from Sherlock's body, relishes in it. He turns his face, feels the warmth lick at his cheek and sighs again; damn near perfect, he feels.

This moment is damn near perfect. Bottle it, wrap it, keep it locked up tight to recall and relish. Bottle it, wrap it, pretend that it doesn't exist.

They sway for minutes, hours and though he can't pinpoint how long they've been holding one another, John feels as though it simply hasn't been long enough. His body feels different, as though he's taller, as though there's no height differential between he and Sherlock, as though they're not the people that they usually are. They're ethereal, they're so much more than two bodies and a melody. This, this is the exact sensation he wishes he could describe, wishes he could explain to Sherlock.

But there aren't words, and John is so thankful for that, thankful that he's able to shift his hand lower on Sherlock's back, that he's able to share this experience with him.

The fire takes the opportunity to lash out with a particularly boisterous 'pop!' and John startles, falters and loses his steps. Sherlock sighs, blinks so slowly and begins to lead, moving their bodies slowly and fluidly around the threadbare carpet. He begins to lead as though it's an inherent skill he never knew he had.

The song ends and shifts into another, giving them ample opportunity to end this, to end whatever this is. But Sherlock tightens his fingers around his bicep just enough and they continue moving, nothing but the rasp of socks on carpet and the nothing outside the window.

Catharsis and something like subterfuge, but nothing so intentional. John feels pink in the cheek, guilty as sin and he isn't sure why. There was no purposeful deception behind any of this; John's conscious he wasn't even certain that this was something he needed until it happened. Sherlock's scent isn't simply overwhelming, it's effervescent, enveloping him. He's never encountered something so positively heady.

And it's too much, it's too much. "Sherlock," he begins, not ready but willing to end their experiment. It's a necessity; it's all going to unravel if this doesn't come to an end soon. It's all too heady and John feels it, feels endorphins and the unknown rush straight to the top of his head and make him just a tad dizzy.

There's the curve of Sherlock's neck, right before him. Tendons and muscles conspire to unravel him; they're taut as though attempting to keep something tenuous in check. There's the set of his lips, those too are set in a line that John's never seen, as though pressed together in something like concentration but something far more serious.

Sherlock's eyes are bright gray (if there is such a color and John believes that there is) and looking pointedly everywhere but at John. His body is no longer rigid but pliant and John isn't sure when that happened; he's been too wrapped up in his own thought and it devastates him.

That he didn't record the exact moment when Sherlock totally acquiesced to him.

"John," voice low and purposeful and not wavering now but so, so strong that John's sure there's extra care to be sure that the voice doesn't waver.

"Hm?" John's hand at the waist curls into the shirt and holds.

"Perhaps you should lead. I-"

John breathes out his response, "Yes," and it's that, in that second that he steps right into Sherlock, his head nearly nestled into the space between his chin and shoulder. "That's probably for the best."

It's too close and not close enough. John's teeth long to test the strength of those muscles, wish to rasp over Sherlock's skin just there. The very tips of his fingers dig into his hip, hard, too hard. Sherlock's breath rasps, his eyes slam shut and he buckles.

Only a bit.

John wouldn't notice if he hadn't been holding him.

The fire is dying, embers snapping against fresh oxygen and the track melds into something slow and almost too quiet. It intrudes upon the moment and John finds himself stopping.

Sherlock's eyes peel open, left, right and then gaze down upon him, John's face in shadow from the fire and kitchen fluorescent. John's fingers still against Sherlock's back and Sherlock's palm still clenched against John's bicep. Too hard, too close, too intimate-

Not enough.

Sherlock is the first to come back to himself, sucking in fresh air and disengaging himself in a fluid maneuver. He smooths out his shirt as though he's been mussed by their gentle swaying. John follows suit, slides a hand into the pocket of his slacks, takes it out, can't remember what to do with his hands.

Though Sherlock has his back turned, is gazing at the fire, the emotion behind his words is clear. "I understand."

His eyes fall closed and John lets a breath go, a breath he didn't know that he had been holding. He smells like Sherlock; he can smell him on his jumper, can still feel the heat from his body on his own and it's-

Too much.

Not enough.

A massive amalgamation of everything.

"Sherlock-"

"She killed him because she loved him and she didn't know how to have him," he's quiet for a moment but then turns on heel, strides to the door and snags his coat. He's scarved and buttoned up in a matter of seconds and he looks up at John under a tangle of hair his eyes very nearly liquid.

"Are you coming?"

John grabs his jacket, follows him down the stairs.

Sherlock leads, again.