i.

It began when Sherlock was eight, and he attempted to climb all the way up to the highest branch in the old willow tree in his back garden.

He'd thought he was still small enough that it could support him, but the second he'd grabbed hold of it to pull himself up, the branch snapped, and down he went, plummeting a solid twenty metres.

The odd thing was, he never actually hit the ground.

Well, that wasn't precisely true. He ended up on the ground, but he didn't hit. No impact. One second he was falling, the next he was simply lying on his back in the grass, as if he'd tripped.

He blinked up at the bright blue sky for several long moments.

Well, that was interesting.

ii.

Sherlock wasn't stupid. That fall could have easily killed him, and while he was still too young to have a full grasp of linear projectile physics, he knew quite well that people could not simply bypass inertia. When he mentioned the incident to Mycroft, all he got was a long, disinterested look and a haughty sniff. Well, that was fine. He'd not expected him to be much help anyway, the lazy sod. Mummy was away on business, so he couldn't ask her, and Father never paid any attention to him anyway. He could probably go careening naked through the house and not get so much as a sideways glance from him.

Sherlock would have to get to the bottom of this on his own.

Obviously, he needed more data.

Sherlock managed to slip out of Holmes Manor without any of the servants spotting him. It wouldn't do for them ask what he was up to. He'd grown to be quite the convincing liar, but they were accustomed enough to his morally-dubious ways by now that they might still be suspicious. Best to avoid them entirely.

It was overcast but thankfully not raining. Yet. He could smell the impending moisture in the air, heavy and sharp. Sherlock followed a winding stone path through rows and rows of white rose bushes until he reached the willow tree—large, elegant and very, very old—and began to climb, following the familiar path of branches that he'd been scampering up since he was big enough to reach it.

He climbed three-quarters of the way up and stopped at his favourite branch: thick, nearly straight (well, for a tree), and just flat enough that he could lie down and read if he liked. Sherlock scrabbled onto it, his right hand braced on the trunk for balance, and peered down. He was at least fifteen metres off the ground, and there were plenty of other branches he could easily smash into.

A wave of vertigo hit him, and he gripped the trunk harder. It was one thing to fall. It was entirely another to jump.

"Don't be a ninny," he whispered to himself. "This is for science."

Sherlock steeled his nerves, closed his eyes and jumped.

The second he hit open air, he regretted his decision. A strangled cry tore unbidden from his throat, and he waved his arms uselessly. He was going to break a leg at the very least, if not do some lasting damage to his spine.

Abruptly, and in a thoroughly disorienting transition, Sherlock was stood on the ground. He stumbled, confused by the discrepancy between where he was and where his brain said he should be. He looked down at his feet. Springy, bright green grass lay beneath his trainers.

Sherlock craned his neck back up towards the tree. The branch was right where it was supposed to be, high above his head.

What the deuces was going on here?

"Magic tree?" he mumbled to himself before shaking his head. That was stupid. Magic wasn't real. It had to be some sort of . . . flux in the Earth's gravitational force. A flaw in the deep gravity well. Something.

Sherlock scrambled to climb back up, all his fear evaporating as his mind blazed through a thousand possibilities.

Sherlock had just put his hand on the first branch, however, when he was yanked back down. He whirled about. There was no one there. Cautiously, he stood up on tiptoe and reached for the branch. Again, something pulled him away, harder this time.

Sherlock turned a full 360 degrees, eyes darting quickly over the nearby bushes and flowers. He would have heard leaves rustling if someone had hidden, and honestly, who could hide from him?

"Mycroft?" he called tentatively. "Mycroft, if this is you, I'm going to poison your custard. Again."

There was no response. Keeping an eye on the bushes, Sherlock reached up again until his fingers touched wood. This time, he felt it distinctly. A hand—some form of invisible hand—fisted in his shirt and yanked him away from the tree. Sherlock stumbled forward and only barely caught himself. His head whipped around, but he still saw no one. There was no mistaking that feeling. A hand had pulled him away from the tree, but he was definitely alone. Well, perhaps not. Sherlock's veins flooded with ice.

"H-hello?" Sherlock asked shakily. "Is anyone there?"

There was a pause—a beat of silence so thick with anticipation, it stole the breath from Sherlock's lungs—and then he felt it.

A gentle brush of fingers against his cheek, a warm hand settling on top of his head, and then it was gone.

Sherlock stood stock-still, his eyes open wide as his brain whirred.

It wasn't possible, and yet . . . .

The only thing Sherlock could tell for certain was that the second the hand had touched him, all his fear had vanished.

iii.

Sherlock's invisible protector came to his rescue twice more: once, when a bully at school attempted to hit him with a lead pipe but then suddenly found himself on the roof of the school, and again when Sherlock had a brief flirtation with motorbikes that led to him spinning out in front of a lorry. He'd walked away from the smouldering remains of his bike without a scratch. The EMTs had called it a miracle. Sherlock had simply smiled.

No amount of research had been able to explain the phenomenon to him, and beyond his one feeble attempt with Mycroft, he'd never attempted to tell anyone. It simply . . . was. Sherlock had some sort of immunity to serious injury.

It would take years, but Sherlock would eventually come to understand just how vulnerable this made him.

iv.

To his parents' immense shock, when sixth form ended, and it was time to head off to uni, Sherlock agreed to go to Cambridge, where all the prominent members of his family had attended for the past hundred years.

They took the news warily and with no meagre amount of suspicion. They did, however, congratulate him on his acceptance to one of the top universities in the world (frankly, Sherlock's disciplinary record had nearly got him rejected. Father had been forced to make a phone call) and offered to help him move into his new dorm. What they failed to realise, however, was that it didn't matter where Sherlock went to uni. He didn't care. If he'd had the choice, he'd not have gone at all, but he knew if he so much as proposed that, he'd be packed away to some hateful boarding school in Switzerland before he could complete the sentence. At least this way he got to stay in the country, and he would be able to make use of the university's extensive Chemistry department until his marks inevitably plummeted and he was forced to drop out.

Sherlock hadn't the faintest idea what he would do after that, but he had a feeling something would come along.

v.

That "something" ended up being a man by the name of Victor Trevor. Sherlock met him his very first day of uni when Victor took the seat next to him in maths and said hello. Sherlock proceeded to loudly announce that Victor was sleeping with their TA. Victor, to Sherlock's immense surprise, then said even more loudly, "Yes, and you should hear the sounds he makes. They're positively filthy."

The TA rushed out of the lecture hall with downcast eyes and a burning face, but Victor merely folded his arms behind his head and grinned.

Sherlock was admittedly intrigued.

"So," Victor asked casually, "have you been spying on me, or are you as clever as you look?"

vi.

Victor was a puzzle that Sherlock couldn't quite suss out. He was from a posh, titled family, but his T-shirts had holes in them, and he habitually refused to wear shoes. He smoked rolled cigarettes—and promptly taught Sherlock how to roll them—and put no effort whatsoever into his honey-brown hair, yet it was always an artful mess. He was whiplash smart, not as clever as Sherlock by any means, but much sharper than their peers. And he knew things Sherlock didn't.

Victor's knowledge bank centred around subjects Sherlock had long since dismissed as useless (i.e. anything that wasn't a hard science), like anthropology and psychology. He told Sherlock one day that the reason police officers always suspect the husband is because statistically speaking, when a wife shows up dead there's a one in three chance he offed her. He then went on to detail a case he'd read about recently where the husband had used a plastic gun to kill his wife and then dissolved it in acetone, completely destroying the murder weapon. It had been a nightmare for the police to solve, apparently. Sherlock was surprised to find himself fascinated by the information. The next day he went to the library and checked out as many texts on criminal psychology as he could get his hands on. Not so useless after all, it seemed.

The most puzzling thing about Victor, however, was the fact that he appeared to genuinely like Sherlock. No matter how often Sherlock insulted him, Victor just laughed it off and then asked him if he wanted to smoke a spliff. It was irritating and captivating, and Sherlock began to fear he might be in serious danger of falling in love. The idea alone was loathsome.

He needn't have been concerned, however, because one month into second term, Victor introduced him to the love of his life: cocaine. Sherlock, accustomed as he was to his apparent invincibility, took to it with reckless alacrity.

It took him less than a month to OD.

vii.

If Sherlock had known how thoroughly the overdose was going to change his life, he would have stuck the needle into his arm that very day.

viii.

"Sherlock! Sherlock, look at me. Look at me! You've got to stay awake, Sherlock, please."

Sherlock blearily opened his eyes, but nothing they saw made sense. It was like looking at the world through an unfocused camera lens with black squiggles dancing round the edges. His brain moved sluggishly, attempting to process information through the thick haze of drugs pumping through him.

He was lying on a cold tile floor, looking up at a ceiling—his kitchen ceiling. His skin was burning, bubbling, itching, like a living thing was slithering about just beneath the surface. He had two strong desires: to sleep for at least three years and to vomit. He'd just settled on the former when the voice started up again.

"No, Sherlock, don't you fucking dare! I swear to God, if you go to sleep right now, I will never forgive you. You can't do this to me, Sherlock. I can't let you die, but I can't save you this time either. I can stop you from falling or from getting hit by a lorry, but if the drugs are already in your system, I can't do a fucking thing. You have to stay awake."

"You're not Victor," Sherlock said blearily. He could make out some things, but not much. Male. Tan skin. Blond Hair. Green shirt. "Who are you?"

"I'm—" the voice hesitated. Then, "I'm your friend, Sherlock. Just hold on. The ambulance is almost—"

The world went black.

ix.

Sherlock had considered the concept of eternity on numerous occasions and had concluded that it was a horrific one. He got bored of things so easily, and if given enough time—if he had all the time in existence—he would run out of things to grow bored of. And then there would be nothing but his own mind, trapped in infinity, with nothing to occupy it, and he would most assuredly go mad. If there were such things as evil spirits, he imagined that was where they came from. They were driven into insanity and rage by the monotony of being.

Better to die one day and find nothing waiting on the other side. The end. Good night, Vienna. No more boredom. No more chasing after an unending stream of puzzles that could only satisfy him for so long.

Of course, thinking about death and being faced with it are two very different things.

As Sherlock floated in darkness, cognisant enough to be aware of himself but nowhere near able to suss out where he was, the idea of death, of floating here forever in a vacant abyss, was the most unbearable hell he could have possibly imagined.

x.

"Okay, you've got questions."

Sherlock blinked owlishly. His hand was still half-hovering over the call button, but he knew he wouldn't press it. The sterile odour of the hospital was heavy in his nose, and his head hurt, and he really just wanted to go back to sleep, but finally, finally something interesting had turned up.

A short, well-built blond man was sat by his bed, leaning forward with his chin in his hand and a warm smile on his face. That wasn't what had made Sherlock nearly call the nurses, however.

The thing was, this man couldn't possibly exist. Sherlock's eyes swept all over him, taking in his terrible beige jumper and his brown eyes—no, blue. Very dark blue—and his tan lines, and . . . it just couldn't be.

Sherlock could read nothing from him. From his clothing to his face to his words, Sherlock could see nothing but the obvious. Male. English. Looked about the same age as Sherlock, so late teens to early 20s. Useless. The little that Sherlock could deduce made absolutely no sense. According to his eyes, nothing on Earth had ever touched this man. No person had ever laid a single finger on him, no food had passed his lips, nothing. It was as if the man had popped onto the planet one day, already fully grown. There was also something . . . off about him. He looked solid, yet intangible. The man was there and not there simultaneously, suspended in some odd almost existence between one blink and the next. Sherlock felt the hair on the nape of his neck rise.

"What are you?" he asked carefully.

The man, to his surprise, chuckled. "I knew you'd get it in a tick. You're amazing."

Sherlock couldn't hide his surprise, and the man laughed again. "Not used to having others appreciate it. I know. I've had to stop myself from tying all your schoolmates' shoelaces together for fifteen years." The man stood, and the air about him shimmered strangely, as if heat waves were radiating from him.

"You can call me John," he said, still smiling in a way that made something in the back of Sherlock's mind niggle, "and trust me when I say I mean you no harm. I've to go for now—Dad will want to know how you're doing—but I'll be back. No point in hiding now that you've seen me."

Sherlock blinked, and John was gone.

Sherlock whipped up into a sitting position. His head immediately rebelled, but he ignored it. The door to his hospital room was closed. Even if it weren't, there was no way the man—John—could have reached it that quickly.

A fresh jolt of pain made Sherlock lay back down.

John. An impossible man. Hm, interesting.

xi.

"I'm a daemon." John took a sip from his tea mug and grimaced. Too hot, Sherlock deduced. He could see the steam from five feet away.

"A demon?" he parroted. Sherlock was sat on the headrest of a squishy, old armchair he'd rescued from a skip, with his feet on the cushion and his hands folded beneath his chin as if in prayer. They were in his dorm room, and his roommate was thankfully elsewhere. It spared Sherlock the effort of viciously kicking him out. His eyes were intent on John, darting from his face to his shoes to his chest and back again in rapid succession, drinking him in.

"Common mistake," John said. "Daemon. Big difference. We're not human, like demons, but unlike them we're benevolent. We can turn evil sometimes, like in the case of the Lamia, but generally we're good."

"What's your purpose?" Sherlock demanded, probably harsher than necessary, but his curiosity was piqued, and he wanted John to speak quickly. "Why did you help me when I overdosed?"

"I've been watching over you since the day you were born."

Realisation slammed into Sherlock so forcefully, he nearly fell off his chair.

The tree. The bullies. The motorbike accident. Oh, novel.

"So, what are you, my guardian angel? Do you have a white robe and wings and a halo tucked away somewhere?" He made no attempt to keep the sneer out of his voice.

"Daemons aren't angels by any means, and no, we don't have wings. We are, however, assigned to a human at their birth and then protect them all their lives. I'm a part of you." John waved vaguely to Sherlock's body. "I've been a part of you from the moment you took your first breath. I always will be."

Sherlock felt a pang of something unidentifiable in his chest. "Obviously you have a physical form and can touch things." Sherlock gestured to the cup of tea John had made. "How does that work?"

"Like I said, I'm a part of you. If you can touch something, so can I. If I want to be invisible or incorporeal, I can be—hence why you never saw me until the overdose—but I wouldn't be of much use to you if I couldn't interact with your world. How could I haul you out of a burning building or push you out the way of a bus if I couldn't touch anything?"

"Something about you looks wrong, though, like you're here and yet you're not. Why is that?"

"We exist simultaneously in this world and in something called the aether. It's a discrepancy in the space-time continuum, the same that allows for all the sundry oddities of life, like luck and karma and miracles. When you get a funny feeling about someone that you can't explain, that's the discrepancy."

Sherlock snorted. "I simply call that being observant."

"Well, not everyone is as delightfully observant as you, Sherlock. Ordinary people rely on things like instincts and a spot of good luck. As I was saying, that all stems from this little blip in reality. You'll like this bit; it's more science and less magic. Daemons like me are here on Earth, but we're also a fraction of a second ahead of you. Parallel to you. It's why we can prevent bad things from happening to our charges. In our intangible form, in the aether, that fraction of a second feels like years. The aether contains all sorts of things, though: lost souls, bits of misplaced history, even the odd object that's somehow got lost in it. Think of it as a cosmic junk drawer in God's house. It all exists in this world as well, but because of the discrepancy, it can't be reached."

"Since we're on the subject of God, who created you? Who controls you?"

"No one controls us." John gave him an austere look that Sherlock pointedly ignored. "We were created by a god, a very old god. You would know him by the name Zeus, unless you've deleted Greek Mythology."

Sherlock couldn't help but laugh. "Zeus. The King of the Gods? The one who faffed about getting women pregnant and turning people into swans? That Zeus?"

"The stories are somewhat exaggerated, but there is some truth to them. 'Zeus', as you lot call him, is one of many gods, just like in the myths, but he's certainly not the king of them, and . . . well, he admittedly has a flair for the dramatic. As a result humans became aware of him. Glaringly aware of him. And so Greek mythology was born. Fascinating, yeah?"

Sherlock tried to suppress a rictus of disgust, but judging from the way John burst out laughing, he failed.

"I know, I know, Dad has a bad rep, but trust me when I say he's a good bloke. Certainly a hell of a lot more entertaining than Ganesh. Always juggling, that one. Besides, how bad can Dad be if he sends us daemons out to watch over you lot? He created us for you, you know. Protecting you is our top priority."

Sherlock deftly changed the subject. "Why did you reveal yourself to me?"

"I didn't. Not consciously, anyway. I was just suddenly corporeal. It's part of my biology: a defence mechanism, so to speak. When a daemon's human is in danger that we can't prevent from the aether, we instantly appear in this world so we can interfere directly. It's instinctive, faster than thought itself. Some humans go their whole lives without ever meeting their daemon face to face, but plenty don't. You're far from a special case."

"Does everyone have a daemon?"

"Oh, gods, no. They did back in the day, but do you have any idea what the population growth has been like on this planet in the past hundred years alone? God or not, Dad can't keep up with you. No, you're just one of the lucky ones."

"Why me?"

John shrugged. "There's always something special about the humans that are chosen. Sometimes it's something big, and sometimes it's something small. William Shakespeare had a daemon, for example, but so did most of the people on Flight 93."

"If they had daemons, why were they killed?"

"We're not infallible, and if a person has a greater purpose, we can't interfere with that. I dare say those people did."

Sherlock fell silent, his brain racing as it processed this new information, filing it neatly away. After just the slightest moment of hesitation, he said, "Tell me more."

"About what?"

"About you. What you do. What you are." He raked his eyes up and down John's seemingly unremarkable form. "What are you made of? What are you capable of?"

"I've covered some of that already, but here, I've a fun fact for you. You know how the Romans basically copied everything the Greeks had in their mythology and just changed the names?"

"Yes."

"Guess what they called us."

"I never guess."

"Yeah, you do."

Sherlock paused. "What?"

"Geniuses."

Sherlock raised a brow.

"Well, in Latin it's genii, but nobody speaks that anymore. It was because we guide humans throughout their lives and help to lead them down the correct path. I thought you'd find that interesting." John drained the last of his tea and set the mug down on the coffee table. "As for what we're made of, the closest approximation I can think of in this language is energy. Pure energy. It's why I seem to radiate heat. That's how this world interprets what I am. In terms of what daemons can do, when we're in our physical forms, we're essentially just like humans." He pointed to his empty mug. "We drink. We eat. We sleep. We have all the normal biological needs and reactions. In spirit form, however, we have a bit more power. Not as much as Dad, but enough. We can . . . nudge people, in a way. Convince them not to do things or to take a certain path. Like I said, we're not infallible—I obviously failed to keep you from shooting up—but it's usually enough to keep our charges alive and out of trouble." John chuckled. "Though I must say, you've certainly kept me busy these past two decades. I'm never bored."

John smiled again, and suddenly Sherlock realised why that smile affected him so strongly. He could feel it, like the hand on his head when he was a little boy. It was a warm presence that started in his chest and spread through him until it was in every finger, every toe, every strand of hair.

"Well," Sherlock drawled, his face impassive even as his heart beat slightly faster, "what now?"

John shrugged. "Now that you know, I don't have to hide anymore." His face turned fierce. "But no. More. Drugs. Sherlock, you can never do that to me again."

"What do you care?" Sherlock retorted obstinately. "If I died, you'd be released from your duties. Wouldn't that be preferable to chasing after a lunatic who's clearly lacking in basic self-preservation instincts?"

Sherlock tried to keep his face neutral, but when he saw the look that came over John's, he faltered. It was like all the sun and warmth and safety in the world was concentrated in his impossibly blue eyes as he looked at Sherlock.

"I care," he said softly. "You can't fathom how much I care, Sherlock, and if anything ever happened to you, it would destroy me. In every sense of the word."

Sherlock swallowed thickly and forced himself to turn his face away. No one had ever looked at him like that before. Like he was something precious.

"All right," he whispered. "No more drugs." And for the first time in his life, he wasn't just saying what someone else wanted to hear.

xii.

He cut ties with Victor Trevor entirely. It was surprisingly easy, considering just a week ago he'd been the closest thing Sherlock had to a friend.

He had something better now.

xiii.

Sherlock expected to have difficulty explaining where John came from. He had no past, no educational history, no paper trail. Plus, there was that unnerving, not-quite-there-ness about him that constantly made Sherlock's senses skitter. It was oddly pleasant in a way he couldn't describe, like looking at a new colour. His brain couldn't quite wrap around it.

As it turned out, people didn't ask John much about himself. He had a basic story that he told everyone: John Watson, old uni friend of Sherlock's, intends to become a doctor and join the army—but beyond that, no one pried. Sherlock accused John on multiple occasions of "nudging" them into submission, but he only grinned in response and nagged Sherlock to eat more.

The real trouble, however, came just after graduation when they were sharing a tiny flat on Montague Street. Mycroft showed up unannounced and got three feet inside the door before his eyes locked on John.

Sherlock stood, seized by a sudden mad desire to throw himself protectively in front of John. That was absurd, though. Mycroft would have seen it all at a glance. There'd be no fooling him. He'd see John's wrongness as easily as Sherlock had.

To Sherlock's ineffable surprise, Mycroft smiled.

"I was wondering when you'd turn up," he said to John. "With my brother's reckless nature, it was only a matter of time."

"I'd apologise for taking so long," John replied easily, "but frankly I'm grateful Sherlock managed to make it so many years without a complete catastrophe."

"How—" Sherlock rounded on Mycroft, but his voice cracked. "How could you possibly—"

And then Anthea appeared at Mycroft's side. Loyal, dependable Anthea who'd just turned up out of the blue one day and never left.

Sherlock stared at her. Mycroft smiled unctuously.

"It seems we're both destined for greatness, brother dear."

xiv.

If someone had asked Sherlock to name the exact date he'd realised, he wouldn't have been able to.

It'd been over a decade since John had joined him—thirteen years of rows and laughter and danger and adventure and Sherlock nearly getting killed and John scolding him and holding his face and fighting back tears as he screamed at Sherlock to never ever ever do that again and Sherlock feeling this strange longing but not knowing how to fulfil it and John looking at him like he was the most wonderful thing in the world and Sherlock wanting cocaine so badly it ached and him always, always not buying it because John—and suddenly Sherlock just knew.

Maybe he'd always known, from the moment John had entered his life, and he'd simply been too caught up in the Work to notice.

Sherlock wasn't certain how to tell John, or even if he should. Bit not good, potentially. How did these things even work? But then one day they were chasing a criminal, and they managed to get him cornered. They were just about to close in when he pulled out a gun that Sherlock had somehow failed to deduce.

Sherlock's heart began to pound, but when the gunman pointed the barrel at John, it stopped entirely.

He expected his instincts to kick in. He expected some mad urge to protect John to come flooding into him, and then he'd throw himself in front of him. Instead, horror paralysed Sherlock, coursing through his veins like cold mercury. He'd never felt so panicked in his life; it was like a pair of giant hands clutching his ribs, like burning pain that made every inch of his skin crawl. He watched, utterly frozen, as the gunman cocked the pistol and pulled the trigger.

The ground came rushing up to meet Sherlock, and then everything was black.

xv.

"Sherlock! Sherlock, wake up! Oh, you wanker, you would do this to me again."

Sherlock's eyes fluttered open, and a familiar face gradually came into focus. John.

Relief rushed into Sherlock so sharply, he gasped. He tried to sit up, but John grabbed his shoulders and pushed him back down. "No, you don't. You're going to stay right here while I check your vitals."

Sherlock realised his head was resting in John's lap. He stayed obediently still as John shined the light from his mobile in his eyes—"Didn't bring a torch with me, sorry"—and took his pulse, muttering under his breath about a "melodramatic tosser" the whole time.

"All right, you can sit up."

Sherlock did, but he didn't move away, angling his torso so he could look at John. God, he never thought he'd be this happy to see someone's face. "What happened?"

John grinned. "You forget, I don't have to be corporeal if I don't want to be. I flickered into the aether just as the bullet would have passed through me, and then I tackled the bastard and took his gun. Thanks for all your help, by the way." John gestured to the crumpled body of the gunman ten metres away. "I can't tell you what a blast it was to take him out all by myself while you swooned like a Byronic heroine. What came over you?"

Sherlock studied his face, examining the lines and little blond hairs and crags he knew so well. John's face was the one thing he never got tired of looking at. It was so expressive, his emotions written in his brows and the quirk of his mouth. Sherlock thought about how he'd felt when he'd seen that gun pointed at John. New terror gripped his heart and squeezed as he pictured it: John, lying on the ground as blood poured from a wound in his chest. If he'd been hurt, if he'd died, Sherlock knew he wouldn't be far behind him. The loss would kill him as surely as if he'd lost the ability to breathe. The grief would suck the life out of him, and he'd do nothing to fight it.

John was watching him closely, concernedly. Sherlock saw realisation blossom in his eyes, and he breathed, "Oh."

John pulled him into a fierce hug, wrapping his arms around him and holding him close. "Sherlock, I promised I'd always be by your side. I meant it. You must know that. I would never leave you here alone."

"I know," Sherlock gasped, and he could hear the almost-tears in his voice. "I know."

xvi.

"Which part?"

John startled and looked up from his newspaper. "Pardon?"

Sherlock strolled leisurely towards John's chair and stopped when he was just before it, his knees barely touching John's. "You told me once that you were a part of me. I assumed you meant that literally, and my research confirms that daemons have a physical as well as emotional link to their hosts. Which part are you? A toe? A finger? Hopefully not something I could accidentally cut off."

John was still for a moment. Then he smiled slowly, gently, and lifted a single finger until it came to rest on Sherlock's chest, just over his left breast. Sherlock could feel his own pulse racing just beneath it.

"Oh. Oh."

xvii.

They were stood in the kitchen of 221B Baker Street, cleaning up after dinner, when the question that had been on Sherlock's mind for days finally forced its way past his lips.

"So, is it love then?"

John didn't stop drying the dish in his hands, but Sherlock saw his shoulders tense. "I imagine so. It doesn't have to be if that's not what you want to call it." He hesitated, licking his lips, and Sherlock followed the motion rapturously. "We don't have to be anything more than exceptionally close friends, as far as other people are concerned. We, of course, know the truth, but even then, we can just be human and daemon. That's what we are, after all."

Sherlock processed his answer unusually slowly. There was something wrong. Something about John was wrong. In a burst of intuition, Sherlock realised John was holding back.

He put the dish he was scrubbing down and turned to him. "You love me." John finally stopped drying and looked at him with those stunning blue eyes he knew so well. "You've loved me since the day I was born, no matter how insufferable I've been. You've saved my life more times than I can count, and you love me. You know I love you as well, but you've no idea what that concept means to me. You've been with me for every moment of my life, but you've never seen me in love."

John put his dish down and turned to face Sherlock, squaring his shoulders. Moments like that made Sherlock think maybe people didn't question John's story about being a former army doctor because it just seemed true.

"Yes, I admit it," John said, his voice deceptively calm. "I'm not sure what this means to you, but I didn't want to ask, because . . ." he trailed off, floundering for a moment as he tried to think of the right words. Sherlock waited patiently until John finally huffed out a nervous laugh and said, "I've always been perfectly happy just being by your side. Relationships between daemons and humans are notoriously complicated, but nothing can ever destroy the love there. I would have been perfectly content to sit back and watch you live a long, happy life without you ever even knowing I existed." He paused to take a shaky breath. "Just know that you can't make me unhappy, unless you hurt yourself or put yourself in harm's way. I'll always be right here. Whatever you want to be is fine with me, but this doesn't need to be—be anything, really."

He trailed off, looking annoyed at himself.

Sherlock, however, was grinning. "I see. Well, in that case, you won't mind if I do this."

He swooped forward and kissed John before he could stop him. John jumped, clearly surprised, but after a moment's hesitation, he pressed closer, returning the kiss. John's mouth was soft but firm and overly-warm, just like the rest of him. Sherlock had never felt anything so exquisite.

After a minute that was far too short, he pulled back, and looked at John. His pupils were so dilated, his irises were nothing more than rings of blue light around twin black holes.

"Well," John said, a touch breathless, "that settles that."

xviii.

Sherlock examined the corpse on the pavement in front of him with feverish excitement.

"Try not to look so pleased, Sherlock," John hissed. "Dead woman, remember?"

"Oh, but John," Sherlock rumbled, pitching his voice down to the velvety-smooth baritone that he knew made John instantly forgive him 93 per cent of the time, "do you know what this is?"

"No. What?"

"Something new."

xix.

"Sorry, John!" Moriarty shouted in his lilting Irish accent. "I know I said I'd spare Sherlock, but I really can't have him poking about in my affairs any longer. Too messy. Too likely that one of my idiot clients will drop the ball. You understand, don't you?" He batted his eyelashes flirtatiously.

The sound of pool water lapping nearby was eerily hypnotic. The sharp tang of chlorine was so strong it burned the inside of Sherlock's nose with every breath. He blinked as blood dripped into his eyes from the wound at his temple. A man—a tall blond with unnaturally pale green eyes and dark skin—pointed a gun steadily at his head. Sherlock's blood was smeared on the barrel of it from where the man had hit him.

"Moriarty," John growled, his Browning 79A1 in his hands and pointed at the Irishman, "you let him go, or I promise I will—"

"Oh, spare me," Moriarty said with a roll of his eyes. "I know all the usual threats, love. I make them myself on a daily basis. The fact of the matter is, your little pet over there is going to die, and there's nothing you can do to stop it."

The man cocked the pistol, and Sherlock froze.

Please, God, Sherlock thought, let John live.

"Brilliant deduction," John said, "but you're forgetting one thing."

"Oh? And what's that, pet?"

"It seems someone should have given you a crash course in daemon biology."

Several things happened so quickly, Sherlock could barely process them.

The man pointing the gun at his head squeezed the trigger.

Moriarty shrieked.

There was the sound of gunfire.

In a fraction of a second, the man by Sherlock disappeared and reappeared in front of Moriarty.

Blood exploded out of his chest and bloomed in his white shirt.

He crumbled to the ground, and Moriarty fell to his knees, clutching desperately at the body.

"SEBASTIAN! SEBASTIAN, ANSWER ME. NO, NO, NO, YOU CAN'T LEAVE ME!" He howled wordlessly for a minute before it turned into hysterical sobbing. His face morphed between demonic rage and shattered grief. Sherlock could only watch in horrified fascination as Moriarty took the gun out of Moran's limp hand and raised it to his own temple.

"Goodbye," he said in a flat, emotionless voice, "Sherlock Holmes."

Sherlock flinched away, but nothing could have blocked the sound of a shot firing and a body hitting the pool deck.

There was silence, and then Sherlock heard footsteps trudging towards him. John.

"Jesus," John breathed. "I honestly wasn't certain Moriarty was going to care when his daemon died. I suppose even psychopaths can't ignore the bond."

Sherlock took a deep breath and fought back a wave of unexpected sympathy. He wasn't the least bit surprised by Moriarty's suicide. He wouldn't have been able to stand it either. "That was genius of you, by the way. You knew if you shot Moriarty, Moran's defence mechanism would kick in, the same one that brought you to me when I overdosed. He became corporeal in the exact place he needed to be in order to save his human."

"Yes, well, I have my moments." John helped Sherlock to stand and then grinned. "Shall we go home?"

"Oh God yes."

xx.

The moment they got back to Baker Street and Sherlock closed the door behind them, he launched himself at John.

"Sherlock, what are you—mfph!"

He pressed their mouths hungrily together. All the adrenaline he'd felt back at the pool was still coursing intoxicatingly through his veins. John only paused for a moment before he opened under his assault, parting his lips and grasping Sherlock's shoulder hard with one hand. Sherlock dipped his tongue languidly into his mouth, and it was like tasting sweet ambrosia. John's already abnormally-hot body grew even hotter as Sherlock ripped his jumper up to get at his soft skin. He raked his fingernails over John's taut stomach, and he moaned raggedly.

"Sherlock," John mumbled against his mouth, "Sherlock, wait."

Sherlock pulled back, breathing hard. He'd managed to press John up against the wall by the stairs and was looming over him, his forearm resting by his head.

"John," was all he managed to say. He'd never asked why John had chosen that name—because obviously daemons weren't given mundane human names—but at the moment, it was his favourite combination of sounds in all the languages of the Earth.

"Are you certain?" John asked tentatively. "You've never—we've never done this, and—"

Sherlock cut him off with another bruising kiss, and God, John melted beneath him.

"Yes, John, I'm certain," Sherlock breathed, keeping his lips just barely touching John's as he spoke, revelling in the feeling of their skin brushing together. "I nearly lost you tonight, and I will not go another day without having you as close to me as you can physically be. Now, please, God, come upstairs with me."

John took the steps two at a time, and Sherlock followed easily.

Sherlock fumbled with the door and managed to get it shut before John went on the offensive. Sherlock was thrown back against the door, and then John was on him, all lips and hands and hot breath against his skin. Sherlock moaned deeply and tilted his head, exposing his neck. John took the cue and mouthed hotly over it before biting down just above his shoulder. Sherlock felt a jolt of pleasure so intense, it made him shiver. God, that had no right to feel as good as it did. He could feel his cock thickening rapidly. John peppered kisses and nips down his throat until he reached his collarbone, and then he bit down again. Sherlock couldn't stop the desperate noises he was making. He retained just enough cognisance to shove a hand between their bodies and grope for John's erection.

When he found it and palmed John roughly through the fabric of his jeans, the other man hissed. "Yes, Sherlock, don't stop."

Sherlock had a better idea. He slid a leg between John's and slotted their hips together until each of their pricks were pressed against the other's thigh. John got the idea and reclaimed Sherlock's mouth fiercely as he began to rock against him. The friction was sharp, almost painful, but John was warm and alive and here in his arms, and everything felt so good Sherlock thought he might burst.

Sherlock tangled his fingers in John's hair and tried to pull him impossibly closer. His mouth was slick and hot against his, the scratch of stubble adding just the right amount of burn. Sherlock wanted to stay like this forever, wrapped around the one man he loved more than his own life. He could feel pressure building in his groin as he thrust against John, however, and knew he didn't have long.

"John," he whimpered, "sofa, now. I want you to fuck me."

John groaned and tore himself away. "God, the thought alone nearly made me come."

Sherlock grabbed his hand and tugged him over to their sofa, holding his face in his hands and feathering it with kisses as he went. When they reached their destination, Sherlock fell onto the cushions and pulled John on top of him.

"Yes," Sherlock growled at the feel of John's warm, solid weight on top of him. He dug between the sofa cushions until he found the bottle of lubricant he'd stowed there the other day. Just in case. He pressed it into John's hand and then immediately began ripping at their clothes, suddenly appalled by their full state of dress. John just chuckled as Sherlock shucked his shirt and trousers as if he were being timed and then started on John's belt.

"Easy, easy," John said as Sherlock attempted to yank his belt out of the loops in one motion. "There's no rush." John pushed Sherlock's hands away and removed the belt himself, setting it aside. He then popped open the button on his jeans and slowly undid the zip, watching Sherlock intently all the while. Sherlock could have very easily melted beneath the heat of that gaze.

"John," he said again, rolling the name around on his tongue as if he were tasting it. John made a noise that was a hair above a snarl and suddenly flipped him onto his stomach. Sherlock moaned and pressed his hips back until he felt his arse connect with John's hot prick. John trailed a finger down his spine to the small of his back and then slid it beneath the waistband of his pants, slowly pushing them down.

"I swear, John," Sherlock groaned, "if you tease me right now, it'll kill me."

He heard John laugh breathily. "So eager. So desperate to be fucked. Do you have any idea how beautiful you are like this, Sherlock?" John finally pushed his pants all the way down, and Sherlock felt a lubed finger press against his hole. He gasped and shoved his hips back, but John made a shushing sound and rubbed his side soothingly.

"Slowly, love. I don't want to hurt you."

Sherlock braced himself up on his forearm and moaned helplessly as John prepared him, gradually pressing a finger into him and stretching the muscles, then adding another. By the time he made it to three fingers, Sherlock was a quivering mass of desperation. John had found his prostate, and every deliberate rub against it sent electricity crackling up his spine.

"Yes, fuck, John, now," he babbled as John hooked his fingers inside him and made him see stars.

"Thank God," he heard John murmur, "I don't think I could have held off much longer."

"Don't, please don't," Sherlock whined. "Just fuck me. I want you so badly."

He heard John curse softly, and then the fingers inside him disappeared. A moment later, something blunt pressed against him and began to slowly sink in. Sherlock cried out, overwhelmed by the feeling of being stretched and the knowledge that this was finally happening. His John, becoming a part of his body, even more than he already was.

When John was fully seated, he pressed himself to Sherlock's back and kissed the nape of his neck. "I love you, Sherlock. So much."

"I love you too," Sherlock said. "Now, move."

John laughed, his breath a hot burst against Sherlock's sweaty skin. "Should have known you wouldn't let the moment last for long." John pulled out of him and then pushed back in, rocking up against Sherlock's arse. Sherlock moaned luxuriously at the hard, full feel of him and angled his hips up for a better angle.

John made a guttural noise. "Yes, just there. Stay just like that. Christ, you feel so good, Sherlock."

"Odd to hear a daemon use another religion's deity in vain."

"I clearly need to pick up the pace if you're still able to think like that."

Sherlock let out a strangled moan as John was suddenly pounding into him, his rhythm quick and steady. Sherlock had to brace himself against the arm of the sofa to keep himself from being thrown forward with every powerful thrust. John found an angle that made his prick brush unerringly against Sherlock's prostate, and his brain cut to static.

"God, John, yes, like that." One of John's arms wrapped around his chest and held him tightly, and Sherlock nearly swooned at the feel of his weight and warmth. Sherlock reached down with his free hand and began to stroke his prick. The second his fingers wrapped around it, pleasure so sharp it almost hurt flooded into him. This wasn't going to take long at all.

John's thrusts were starting to lose their rhythm. "Sherlock, fuck, Sherlock, I'm going to—"

"Me too," Sherlock moaned. "John, come, now."

He felt John's body shudder on top of him, and then he came hard, hard enough that he had to shut his eyes to endure the intensity of it. He'd never felt anything so good in his life, so right and powerful and good. John rocked into him twice more, and then he shouted Sherlock's name, sinking into him and stilling. A moment later, he pressed a gentle kiss to Sherlock's back and pulled out of him. Sherlock pushed himself up into a sitting position and found John on his knees behind him, breathing heavily.

Sherlock didn't hesitate to pull him into a sloppy kiss, all smeared lips and too much tongue. He kissed him until both their pulses had steadied and their breaths came at their usual, unhurried pace. Then he laid down on the sofa, semen and sweat and all, and pulled John's warm, pliant body up against his chest.

"I love you," John said softly, edges of sleep already apparent in his voice.

"I love you," Sherlock responded, threading his fingers through John's hair. In just a few minutes, John was breathing the slow breaths of the deeply asleep, and Sherlock was left to watch the night shift to day and wonder what he could have possibly done to deserve such happiness.

xxi.

"What happens when we die?"

John nearly dropped the mug he was washing. "Jesus, Sherlock, don't sneak up on me when I'm holding our dishware."

"I didn't sneak up on you. I walked up."

"Yes, well, you could bloody well learn to make some noise when you walk. It's unnatural."

"Says the daemon." Sherlock grinned and pecked John on the cheek. "I apologise. Now, tell me. You can save me from disaster, but eventually I'm going to grow old and die of natural causes. I assume you can't prevent that any more than you can prevent the passage of time. You, I've noticed, have been aging along with me. Actually, a bit more rapidly, I'd say."

John gave him an indignant look, and Sherlock kissed him again. "You're going to look dashing when the silver sets in properly. So, what's waiting for us beyond the veil of life? Heaven? Hell? Insane, debauched Gods that come to Earth to drink wine and frolic with sexually-liberated women? What?"

John laughed and wrapped his arms around Sherlock's neck. "I'm not actually allowed to tell you. Secrets of the afterlife. Existential truths. They're all kept under a pretty heavy lock and key."

Sherlock frowned. "But what if there's nothing there? Or there is something there, but I—"

Sherlock cut off, and John gave him a concerned look. "Sherlock? What is it, love? Something's clearly bothering you."

Sherlock placed his hands on John's hips and rubbed soothing circles against his skin. "It's just . . . I was thinking about what happened at the pool, to Moriarty and Moran. They died together, more or less, but what if they weren't together afterwards? Daemons and humans are different, much as we look alike, and you're a significantly better person than I am. What if we get separated? If I go to one place and you go to another? Or what if there's just nothing there when we die, and I never get to see you again?"

His voice had risen to a tinny, slightly-hysterical note, and John pressed their lips firmly together. For a moment, he just held Sherlock close to him, and Sherlock was grateful for the hundredth time for his solid, reassuring heat.

"We're not going to get separated, love. I can tell you that much. If neither of us meets a death by unsavoury means—and we won't if I've anything to say about it—our bodies will naturally give out at the same time, and then our souls will be drawn together by the bond. They couldn't separate us if they tried."

Sherlock grinned, mollified. "They? And who exactly is they?"

John nipped playfully at the tip of his nose. "Sorry, love. Top secret information. I've got my orders from above to think after."

Sherlock scowled, and John laughed. "You'll know soon enough. Humans lives are short, and then we'll have eternity together."

Sherlock tensed slightly but then relaxed. He must have been wrong before. If John was there, eternity was all the time he needed.

End.