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One month, four days and twelve hours after John Watson shoots a murderer in the chest, Sherlock finally comes to understand his urges.
If Sherlock is honest—which he is, most of the time—they began long before that, started exactly when John first limped into the laboratory.
John is a military man—proud and wounded—and leans on a crutch his body does not require. Sherlock understands the need for crutches: the mental mechanics of it, obviously, but also the lure of something beneath your hand. Or, not in the way that other people seem to—the need for touching is anathema to him—but he understands it in the way he always does, as something he can see and learn and never do for himself.
Sociopaths are known for their complete lack of control, but Sherlock is extremely high functioning.
He's forced himself to be.
John is not a particularly useful doctor, but he's easier to talk to than a skull and can occasionally keep up when Sherlock is inevitably forced to explain his perfectly simple reasoning. He can run tolerably well when Sherlock can distract him from his cane—which is always—and he does not flinch near a dead body.
That is the first interesting thing Sherlock notices.
The second is that of all the people in the room or nearby the room, watching in blank shock from the hallway, John looks the most horrified. He is also the only person Sherlock has ever asked who simply replies, "No, a bit not good."
Sherlock does not believe in a good and evil, but he does understand that people who learn about humanity from the outside often manipulate it the best. It is why wives go back to their abusive husbands, why their murderous little cab driver was so successful. They are the kind of people who react to Sherlock not with "you're a freak," but "wrong answer."
The third is that after John shoots a man they go back and have Chinese takeaway and drink the horrid tea the restaurant includes and they're still laughing. Sherlock offers John his blanket because he does not want it and he wants John to take it, but John shrugs it away. "I'm not in shock."
"Neither am I."
John tilts his head and gestures to the sprawl of their room. "So put it away."
His hands are very steady.
"The police are going to wonder about the killer," Sherlock notes between bites of lo mein.
"What are you going to tell them?"
John holds Sherlock's gaze confidently, all of the innocent bluster he trotted out in the immediate aftermath of the shooting gone.
Sherlock steals some of John's chicken. "That the shooter was obviously mad and will be immediately detectable by his frenetic, tortured mental state."
John is not tortured, or stressed in the way killers and soldiers often seem to be for some reason. He is utterly pleasant.
He is not bothered by Sherlock's skull beyond surprise, and the fact that it creates "clutter"—another term Sherlock does not understand, things are always exactly where he puts them (he does not know why it bothers him that John cannot immediately divine his system, since no one ever does).
John does not mind when Sherlock beats corpses to determine blood flow. He does not stare in disgust, like Donovan, or contempt, like Anderson. His pupils do not dilate nor does blood flood to his face in the classic signs of fear and arousal, as it does to Molly. He seems, if Sherlock is right—which he always is—bemused, and then impressed very soon afterward at Sherlock's deductions.
Sherlock knows better than anyone that some of the greatest killers in history were doctors.
John is hardly the first man to come back from a war with an affected psyche. He may not be a serial killer but he is a killer, and it makes him helpful and vulnerable and archetypal. John is a puzzle that has been solved, and Sherlock can keep him because he is more useful than a skull.
There is the issue of his limp. John still insists that it exists most of the time, hangs onto a phantom pain that Sherlock cannot even begin to guess the origin of. That irritates Sherlock, as he is always irritated when a conclusion is tested by contrary evidence.
But he proves to John that there is no pain and sometimes John doesn't seem to feel it at all, like he doesn't feel disgust or contempt. That makes it within, Sherlock decides, a margin of error.
But there are more pressing problems; namely, Harry.
Harry is several problems.
The first is that discussing Harry makes John go quiet, wide in the eyes and tense in the mouth. It makes him seem even smaller than he is, so alarmingly frail that Sherlock has to recoil before he lashes out.
The second is that John calls her weekly, and when he does he will not be interrupted—not for a freshly dead body, not to send an important text, not to fetch his chemicals or tell Sherlock where the sugar is. It is an hour of John's time that Sherlock cannot have.
"You don't even like her," Sherlock points out after the third time it happens, as they drink tea and ponder their current case.
"Who?" Sherlock can tell John knows exactly whom he means, from the way his hand tenses around his spoon.
"Don't pretend to be stupider than you are."
"I don't like you very much either," John says, with a distinct tremble in his voice that is anger or grief or both.
Sherlock finds that he does not like that.
John does not particularly like people—which Sherlock does not mind—but people like John quite a bit. They remember John, although he is a little man like a million little men in London, quiet and unassuming and leaning on a lie. They want to touch him, to shake his hand and pat his back as if he were the favorite son. Women smile at him and lean towards him and pop out to put their lipstick on when they talk to him. It is very distracting.
Mrs. Hudson's brought him tea and biscuits since he had sent her husband to be executed, even before he had moved into 221b Baker Street. Sherlock had never eaten them, but he had grown accustomed to them, as a routine in his life, and no less than his due. He had assumed that this pattern would continue once he had moved to live in such close proximity to her.
Within a week of their move Mrs. Hudson begins to give the biscuits to John. She pats him on the head and fusses with his soft hair and offers to share her soothers with him when she finds out about his shoulder. She calls him "John, dear" as though he were her own son. They watch terrible television together that Sherlock has never even heard of and he knows they twitter about him from the guilty expressions and shy smiles whenever he walks in on them.
Sherlock cannot understand Maury. He is loud and American and obnoxious, and it is always so disappointingly easy to guess the tests.
He ends up throwing his remote at the screen in disgust.
Then there is Molly. Molly has been annoyingly and often confusingly emotional about Sherlock since she first started working at the morgue. It makes Sherlock uneasy when people do not understand that Sherlock cannot and never will be interested—only John really seems to—but Sherlock has come to appreciate that he barely has to try in order to make Molly give him whatever he wants. He takes body parts at will and scarcely has to say thank you, and in return, he need only put up with terrible lipstick and an astounding incapability to understand disinterest.
She takes to John even faster than Mrs. Hudson.
"Does your shoulder give you much trouble?" she asks, the third time they visit. She is twirling her hair, which she often does for Sherlock, and is smiling.
"Only sometimes," John admits. His usual reticence to discuss his shoulder seems dampened. He sounds impressed, the way he only ever is at Sherlock's deductions. "How did you know?"
Molly's smile grows wider, showing off her ugly teeth. "It's not all dead bodies, you know. I am an actual doctor."
"So am I." John smiles.
"Maybe I can take a look at it for you sometime," Molly suggests, and she steps closer and Sherlock hates it.
"That will be all, Doctor Hooper," he snaps.
Molly jerks as though she'd forgotten about him—about him—and then runs off hurriedly.
Sherlock only realizes he's shown his hand, that he even had hand to show, when he finds John looking at him with arms crossed, frown marring his gentle face. Sherlock wants to bite it, feel the bone under John’s eyebrows against his teeth.
"There's no call to be unkind," John says.
"I was not being unkind." He does not add that the unkind thing would have been to throw her out by her hair. He also does not add that he studied biology as well as chemistry, and would be more than capable of examining John's shoulder for himself. Sherlock imagines the scar tissue would be red and angry, ragged lines along the smooth pale skin of John's chest. There would be nerve damage, just enough to make it hurt more, even under the gentle pressure of Sherlock's lips and his tongue and the very sharp knife he keeps in the bedroom that he has never let himself use.
He thinks about it for a long time that night, in his bed, hooked up to however many patches it takes to keep him in his room and not in John's.
It is only a month after they start living together that Sherlock ventures upstairs at the exact moment that John is coming out of the shower. He is wearing a towel around his waist and he is wet.
"Whatever it is, it can wait until I get clothes on." John is working his wounded shoulder, gritting his teeth and pretending, very poorly, that he is not in pain.
"I need to know how long it would take someone to die from blood loss in 40 degree weather with a wound to the femoral artery." Sherlock wants to touch the scar. He laces his hands behind his back. "Also, try sleeping on your back if the pills aren't working. It will put less stress on your shoulder than sleeping on your side."
"My shoulder's fine."
"It obviously isn't."
"Leave it alone, Sherlock." John turns away from him, reaches for his chest of drawers. Sherlock cannot stand that John is not looking at him, and he does not know why.
"When did it happen?"
"I said leave it alone."
The one thing Sherlock cannot do—especially not here, when John is leaning his weight away from his right leg, and hunched over away from Sherlock and naked under his towel and dripping wet. "The shape of the scar tissue indicates an angle of entry that means you were shot from directly in front of you—possibly you were attempting to shield a fellow combatant. If you fell you would have allowed the shooter a second chance to kill whoever was behind you."
"Why do you even care?" John's voice is muted, less vibrant than ever.
Sherlock can't stand it. He needs John to turn around. "Does it hurt when you touch it?"
His fingers flex on their own accord.
"I'm not going to talk about it," John snaps, whirling to face him. He sounds angry, and by the widening of his eyes and the defensive way he grips the towel, hurt. "Figure it out yourself if you're so clever, but don't talk to me about it."
Sherlock blinks. "All right."
John does not shrink at freshly slain bodies, does not waste time weeping for them when he could be solving their murders. He hungers for a fresh hunt with nearly the same enthusiasm as Sherlock, a shadow of the war he left—the war he won't talk about, the one that left him scarred and limping and alone, that makes him not angry but upset.
Sherlock holds up the various data he has been given by this man, and finds a paradoxical conclusion.
Sherlock wants, with a sudden, breathtaking force he has not felt since he was a child, to hurt someone.
"Tea?" John asks the next day, like he always does when he comes downstairs and Sherlock is already awake and about. Sherlock has not accepted once, and he wonders if John simply does not remember—other people never seem to remember anything, even when Sherlock has attempted to beat it into their heads.
Perhaps, Sherlock thinks with distaste, it is politeness, that arbitrary series of rules he has never particularly understood and only rarely tried to. Politeness is a fool's excuse for his own stupidity, like sobriety.
It takes an embarrassingly long time—four more "tea's?"—for Sherlock to wonder if maybe it is something else.
"Black, with sugar," Sherlocks says the fifth time, only for the sake of experiment. He watches John's face brighten ever so slightly before he limps over to the kitchen. He returns with two cups and hands Sherlock's over silently. He takes special care not to touch Sherlock—a doctor's acuity and kindness. Sherlock cannot decide if he is irritated or pleased, which makes him irritated.
He wants to touch John. He wants to do much more than that.
"There are no biscuits," Sherlock notes, to distract himself and further test his hypothesis. John fetches them silently, a roll of his eyes his only comment before he sighs, takes up his own tea in one hand and newspaper in the other.
Sherlock tastes a biscuit and cannot understand the rush he's feeling. John is a modest man with modest capabilities, like any of the thousands Sherlock has easily bullied or manipulated into doing what he wants. There is no thrill of conquest here, of figuring out what he wants to know.
He has not figured out anything at all.
"Hand me your newspaper."
"What for?"
"Because I want it."
John chuckles, rattling the paper as he leans back into his chair. His voice is warm when he says, "Don't be a prat."
When Sherlock was ten he took apart the neighbor's cat because he wanted to know what was inside. He cannot anticipate what would be underneath John's skin. He knows that John is flesh and bone and scar tissue, like anyone else, but there must be something else he could discover, some chemical compound or anatomical oddity that would explain why John Watson, a man who likes most people and is liked by most people and is like most people, not special in any particular way, can do what no one or thing in the world has ever done.
He can keep Sherlock's interest.
A week later Lestrade calls them for an on-site consult.
Sherlock has not seen John in anything less than three layers since the incident with the shower, and John has not updated his blog at all.
They're called to a house in East Ham, where the streetlights are broken and the rain seeps in everywhere. The body is on the second floor, Lestrade tells them, and Sherlock has three theories before he's even inspected the crime scene. Usually he stands buoyed by his own genius on nights like this, so high on his own intelligence he practically gets hungry. It's one of the few drugs he can still get without Lestrade chasing him down with his hounds in the middle of the night, and the clarity it gives him always makes him feel magnanimous in the etymological sense, great of soul.
It's not working. He squints in the dark like he never does and inhales the wet mold reek of the building and listens to the floorboards creak and he's bored. He itches where he can't scratch, and he doesn't know how to fix it. Anderson is smirking at him like the moronic little weevil he is and Lestrade looks so pathetically confused and he's already figured out the cause of death by the time they enter the building and find Donovan smirking at him like she has anything in her life but a large wardrobe she's wasting on a man who doesn't care about her.
"You're in a fine mood tonight," she notes warily, as though it's something she should be concerned about. She turns to John. "What's gotten into him?"
John gives a minute shrug. "Same as always."
They smile simperingly, like they're old friends, except they're not. Sherlock has known Donovan for years, and he's certainly known John for longer than she has.
"Come on," he says, resisting the urge to tug John away. He's following, at least—like he always does. Sherlock does not feel relieved, forcing himself to concentrate on the rickety staircase. He murmurs without even meaning to, "Watch the steps."
Four point seven eight seconds later, Sherlock hears a curse and a thump. He turns and watches John catch himself awkwardly against the stairs, face twisted in pain as he gingerly tests his knee.
"Idiot!" Something barks inside him and he can't make it stop. "Are you deaf as well as stupid? I told you to be careful. How did they even let you through basic training when you're so completely, utterly incompetent?"
"Sherlock." Lestrade sounds outraged.
"It's all right." John waves his hand like he can dismiss Lestrade's anger that way. "And shut up, Sherlock."
Lestrade seems bewildered, which Sherlock doesn't care very much about. Then he reaches out one hand to John, before Sherlock can think to do it, and John is reaching out to take it.
John has never touched Sherlock. Sherlock knows it's meant to be a kindness but he hates it then. His vision goes white, ears ringing, and when he can see again he has John in his hands, under his hands, pinned against the wall and so very small in front of him. John is a soldier, a man who takes other people apart, and Sherlock could kill him if he wanted.
What does he want?
John is looking just at him, eyes wide and pupils dilated like he's high, like he needs to see more of what he's seeing. John's breath is very warm, sour milk and tea, and his heart is going at least one hundred eighty five beats per minute. He doesn't try to move away.
Sherlock brushes his thumb against the spot on John's coat where he knows the scar is. John twitches, so gently Sherlock almost misses it, and hisses through his teeth.
Sherlock lets go.
Donovan is swearing, he hears distantly, and in the corner of his eye he can see Lestrade's hand tightened into a fist.
Then he cannot hear or see anything anymore except John's small smile and his quiet, "I'll be more careful next time."
For the first time since Lestrade's agreed to let him on the scene, Sherlock takes only the two minutes he's normally allowed.
"I'll be outside," he says when he's finished, and doesn't wait to get a reply before he heads down the stairs.
He stands in the cold and watches his breath turn to vapor and wishes he had a cigarette and waits for John to find him.
He jumps when someone else's breath hits his face.
"What the hell is wrong with you?" It's Lestrade, eyes wide with anger and worry, almost embarrassingly easy to read. Sherlock didn't even hear him come near.
"Nothing."
"That didn't seem like nothing." Lestrade holds one hand out like he might touch Sherlock, but even he isn't that much of a moron. "You're madder than usual."
"I am not mad." Sherlock's back is so stiff it aches. "If that's the conclusion you've come to after all this time, Inspector, perhaps it's time we ended our arrangement."
Lestrade sighs, throwing his hands up melodramatically as if he weren't already telegraphing disgust in every fiber of his being. "I don't know how John puts up with you."
Sherlock doesn't know either.
Another problem is that he likes to watch John eat.
John hunches over his food like he hunches over his shoulder sometimes, and he takes small, careful bites. He is polite, fastidiously so, and his diet choices are healthy, tediously so. He eats very quickly like he thinks the food might be taken from him at any point. The army could have given that to him, rations and battlefield wariness. Or it could have come earlier, when John was smaller than he is now. Something ugly in Sherlock leaps up at that thought, something he has controlled very tightly since he killed the cat when he was a child and his brother had punched him in the mouth.
He sips his tea and watches John's throat work as he swallows.
Sherlock watches people eat all the time, and he has only ever been filled with revulsion. He has never wanted to feed anyone before, to run his fingers through their hair, to lick away the tempting dash of sauce on the side of his mouth. John has a mouth like a cat, small and perfectly formed, surprisingly delicate.
"You're staring," John points out mildly.
"You've got a bit of—" Sherlock wipes at his own face, deflecting hurriedly.
"Oh, right, sorry."
When John is embarrassed he smiles. Now he hides it behind a napkin, and Sherlock wants to tear it away. He watches John eat and he wants to grab his face and tear his mouth open and lick his lips open and swallow his smile and bite at his tongue until it bleeds and lap it up when it does.
Sherlock wants all these things and he doesn't even understand why.
Sherlock catches himself at the threshold of John's room in the middle of the night, watching John's ribs move with his inhales and exhales and wanting to run his hands over every one of them, the thick round of the bones and the delicate intercostals, feel the press of organs underneath. There has to be something inside John that will explain everything, how such an ordinary man has fascinated Sherlock so extraordinarily. Sherlock could cut him open right now and find it, touch it with his hands like a true scientist, lick and bite and taste it.
He staggers forward, the ground shifting underneath him, leaving him painfully off balance. He needs something to lean on, and all he has is John.
"John," he murmurs without meaning to.
John sits up immediately, too fast for Sherlock to follow. He blinks dully, watching John grow closer with each slow raise of his eyelids.
"Christ, you're a sight. What have you done to yourself?" He's staring down at Sherlock's arms, and Sherlock finds seven patches on them.
That explains a few things.
But not everything, he reminds himself, as John carefully guides him down the stairs to his room. He keeps to Sherlock's shoulder, layers of cloth beneath them, the kind of politeness that Sherlock has always demanded and never really understood and really hates now.
"I hate it."
"I know," John says somewhere near the back of his neck. "Come on, in you go."
That's what Sherlock wants: inside. He wants to be inside John. He can admit it now, as he falls onto the bed and watches John peel the patches off so quickly Sherlock can't even feel the sting of them tearing off his skin, the neat pads of John's fingers. He wants to peel those off, carve back the skin—not like carving a dead body, the slow slough of cells that are getting in his way. He wants it quick and violent, like the patches ripping off him. He wants to take and take, more than any man can offer, even John.
"I'm going to kill you one day," Sherlock slurs, too tired to hold it back anymore.
There is a dry, chapped pressure against his forehead and Sherlock realizes that it is John's lips. "In the morning, then, after you've slept."
Sherlock does not sleep. Instead he watches the ceiling drift in and out of focus and remembers when Mycroft had first started working for MI6. He'd met Sherlock for lunch, eaten messily in front of him for an hour, and then said between bites, "Just remember, Sherlock dear, I still won't be covering up any murders for you."
>
Three days later, Sherlock tears the semtech from John's chest and wants to keep on tearing.
Moriarty comes back. Sherlock shoots and John tackles him into the pool.
His hearing comes back slowly, after he's choked out all the water and started shivering in the cool night air. There's a blanket on him over his damp clothes, someone shaking him.
He recognizes the touch even through the cold and wet and reeking wool. "John."
He feels like the explosion is still rattling through him, jerking him through the air, off balance and deaf and half blind, drowning while John touches his face like he's checking for fever.
"Let's go," Sherlock says, giving everything away in the sound of his voice, but John doesn't notice or doesn't care or misdiagnoses, maybe thinks it's shock when it isn't, it isn't.
"Let's," John agrees. "But, ah, you might have to help me a bit."
John is heavy and unsteady in his arms, staggering away from the ambulance awkwardly. He should go to hospital, Sherlock knows, they both should, but all Sherlock wants to do is go home and keep John safe. He wants to lock John up forever, and John is following him as fast as he can manage.
Sherlock barely locks the door behind him before he throws John against the wall. There's no hesitation this time, not with the image of John in that coat still seared into his retinas, with Moriarty's threat to tear his heart out still in his ears. He leans in, the press of skin-to-skin electric, his cheek against John's neck and he just breathes and breathes.
"Finally," he hears John say, muffled by the collar of Sherlock's coat. He needs to take it off, tear John's clothes off, get them naked. It's a fever inside him, this need, sweating out his pores.
He bites John's mouth closed, swallowing whatever inane thing he was going to say that could not possibly be as important as this: John's lips on his, John's mouth opening for him, the taste of him, the smell. He's pool chlorine and explosive residue and just John, the way his room smells, the way half the flat smells now. Sherlock bites and tastes and sucks, lapping at the raw cut on John's lip, worrying it until it bleeds again. The chemistry is completely wrong inside him, reactions no natural law can explain, but he needs this and he doesn't care anymore, not about natural law.
John is pushing him away and Sherlock can't have that, he won't. He pushes back harder, like he always does, the way he's always driven everyone away but John. John is backed against the wall and saying something, low, just for Sherlock: "This is much more fun with clothes off, I promise."
Sherlock agrees. He tears his own off, sends them to the floor with a wet flop and forgets all about them. John is going too slow, weak in the shoulder and half off balance and Sherlock can't wait any longer. He grabs at John's clothes, the stupid sweater and sad little buttoned shirt and the trousers that always fit so perfectly, his waterlogged boots. He wants the knife he keeps in his bedside table, wants to cut them off, tear John open with his teeth.
"Get back up here," John mutters when he's naked or close enough, one stubborn sock still sticking to his foot. Once upon a time Sherlock had an internal sense of order, would have needed the symmetry of two bare feet, but now he can barely concentrate past his need to touch as much of John as possible.
The scar is finally, finally bare, flushed from the jostle of their confrontation with Moriarty, tempting as mysterious suicides, as unexplained threats and pictures. Sherlock bends without consciously deciding to, has to shut his eyes as he gluts himself on the wrinkled flesh.
"Bed," John stutters.
Sherlock could flay John open right here, where it would stain the walls and everyone would know. The room spins at the idea of that, everyone knowing, no one ever being able to touch John again. He follows with blind hunger, doesn't even understand how predatory it is until John is in his room, in front of his bed, naked and needy and completely, utterly Sherlock's.
He pushes John onto the bed, thrilled to purring when John goes, spreading his legs so Sherlock can crawl between them. His cock is hard.
"I want to cut you open," Sherlock admits. "In fact I fully intend to."
"Do it," John begs. "Do it, whatever you want—cut me, fuck me."
He scrambles for the knife he keeps in the bedside, under the magnifying glass and next to the hand cream, everything in its place. Except for John, who's getting up when he should be down, lying on Sherlock's bed and waiting. He pushes John down harder than he means to, enough to jostle his shoulder, but John just pulls him in. "It's all right, it's all right, come on, do it."
John is an ordinary man—even ordinary men have preferences, prefer a rough tough or a knife's edge to a kiss. Only John seems to want both, pulling Sherlock's face closer with one hand and the knife with the other, hiccuping into Sherlock's mouth when the point reaches his flesh, in the meat of his thigh.
John lies back, leaving the knife in Sherlock's hands. He's starting to bruise from the force of the explosion and his scar's a raw angry red. There's dirt and filth all over him and now a new cut under Sherlock's blade.
Sherlock is so hard he feels dizzy.
He watches the knife travel up John's thigh, nipping in and then back out, like he's focusing binoculars. He hunkers over, kneeling between John's legs, and hasn't felt this focused since he was ten and discovered the way living flesh twitches under a knife for the first time. John is unpredictably responsive, shying away when he dips the blade into the divot of his hip, leaning in when he skims the fat and muscle of his stomach. He follows the messy trails of blood with his tongue—he can't predict where they flow, can't deduce anything but what he needs right this second.
He brushes John's cock with his neck, has John thrusting up against him, hot skin and wet against the hollows of his throat. He leans back, licking the last sticky drops of blood from his mouth, and wraps his hand around John's cock.
"God, that's good," John moans. He reaches out. "Let me."
Sherlock bats his hand away. He wants John touching him but he wants this more, touching John, memorizing him, cataloging him away where he can never be forgotten. "Let me do this."
John's cock is hot and thick and slightly curved, veins pulsing under Sherlock's fingertips, flared head purple and responsive. If Sherlock circles the right way, John whines, hips jerking, and if Sherlock presses just so, John's head tilts back like invitation, eyes closing as he grips the sheets. There's pre-ejaculatory fluid gathering at the head, slipping down in the divot onto Sherlock's thumb, and Sherlock lifts his hand up and licks it off before he can analyze further. John's eyes snap open as he pulls his thumb out of his mouth. His pupils are swallowed in iris, wide and unreadable.
"Do you have anything?"
Sherlock has to shake his head before he can process the question. "What?"
"You know, lube, condoms—anything."
There is nothing. Sherlock has never had to plan for this situation, has never even considered it.
"I've got some in my room."
"No." The thought of John leaving even for a second is unbearable. He keeps John down with one hand, reaches for the hand cream with the other. "This will do."
There's a scientist trapped inside him who says it won't, knows so even without any personal experience, but John is here and spreading his legs wider and that shuts him up very quickly. The lotion is cool where John is warm and Sherlock slicks it over his cock as fast as possible.
He pushes in.
"Ah—fuck—Jesus, Sherlock, fuck." John is tight and hot and human around him, swearing and scrabbling against his back with his right hand, the left still pinned where Sherlock wants it, that scar held tight and tempting for his mouth. He licks with dedication, wants to imprint every bump and wrinkle on his tongue, every shiver he can wreak out.
He thrusts as hard as he can, needs to get inside John as far as possible and it's not working. He needs more: more sensation, more intensity, more John. He needs more of John's tight pull around his cock and the smell of his sweat and every noise he's making low and strained as Sherlock shoves into him. It's brutal and low and completely unscientific and Sherlock needs it, needs John to need it.
"Harder," John demands, just like always—like he knows exactly what Sherlock needs and will give it to him without a second thought. He's got his hand wrapped around his own cock, jerking so fast Sherlock can't follow the motion. "Harder, harder."
John comes seconds later, eyes wide as when he watched Sherlock deduce for the first time, slightly disbelieving. He gasps, melts like he did after Moriarty, like he can't hold himself together, and it makes everything in Sherlock tighten on him and in him.
John's hands are greedy, reassuring. "Come on, keep going."
John has always loved danger as much as he hungered for mediocrity. As Sherlock pounds into him hard enough to knock the bed into the wall, he has no idea what he is. Everyone does this, this stupid dance of limbs Sherlock has always disdained and now finds himself caught up in. But surely no one does it like this, like it's all that matters, blood on their hands and their lips?
Orgasm steals up on him, pounces on him before he can even recognize what it is. It's brilliant and unfettered, leaves him draped over John, exhausted and surprisingly content, warm in a way that has nothing to do with biological fact.
"Off," John mutters, and pitches him to the side, weakly and with one hand. Sherlock goes with drowsy reluctance, needs to keep in contact with John like they've each been magnetized. John is pulling him closer too, curling his hand through his hair.
Sherlock has never given a sincere apology in his life, and he doesn't want to now. He can't bring himself to feel any remorse for what he's done. He wants to do it again.
"I haven't done anything like that since the war," John says, hushed and content. He's smiling like they're sharing an old joke. "I hope it doesn't take an explosion next time."
Sherlock processes that with embarrassing slowness. "All right," he agrees cautiously, and his hand comes up to John's face, curves against the round of his cheek like it was made solely for that purpose. "But—I’m told I can be a touch possessive."
John laughs, soft and shocking. "For such a genius you really can be the most ignorant man on Earth."
"What are you talking about?" For some reason all the usual harshness in his voice has disappeared. He traces John's eyebrows, the soft skin above his cheekbones. "I'm not joking," he continues. "I don't like to share—at all, ever."
"I know." John's hand mirrors his, tentative until it reaches his face, and then sure and steady as it traces his expression. He has very warm hands, dry and weathered—Afghani sun, a doctor's addiction to sanitizers.
Sherlock blinks. "Oh."
John does not hide his smile this time.
"I still—" There are words for what this is, but since Sherlock has never felt it, he does not know them. He has never seen any use in analogy, and it is worse than useless to attempt to explain it in chemical terms. He says the honest thing: "I want to know what you are inside."
John strokes up and down his back. "You will."
"No." Sherlock shakes his head and sits up. He hates it when people misunderstand him. "I mean I could kill you. You don't even—"
John kisses him. The press of his lips is brief, almost chaste, surprising for all that. "You won't."
Sherlock asks, for the first time in his life, "How do you know?"
John pulls him down and Sherlock finds himself going, curled against John's chest in a way he has always assumed would be extremely uncomfortable and isn't. "Go to sleep, Sherlock."
As he listens to John's heartbeat, the steady rise and fall of his breathing, Sherlock thinks he's figured it out.