NOTE: My apologies for the crazy delay. Classes got busy, work stuff got busy, and I was busy working on drabbles for my "Mathematical Proof" series, which I post on AO3 (look me up there as Bitenomnom). Luckily, I already have significant portions of the next chapters written, so, fingers crossed, updates should be quicker in the future.

Thanks so much to everyone who's reading this, and especially those of you who comment. It really makes my day. :)

... ... ...

Food was the first order of business, John decided when he got to 1989. His only lead was the previous coordinates of the time machine—and he knew exactly where that was from this first journey. It was certainly too far to walk, so he took a cab to a nearby street and stopped at a café on the way for a sandwich.

Of course, John thought as he chewed, he couldn't exactly go up to the door of the houses near where the machine had landed and ask for Andrew. Probably he'd just get the one from the past. But it was something—there had to be a reason Andrew had come from that location.

John took off at a steady march, feeling infinitely better with food in his belly and memories of the belladonna in the past (and, really, really in the past). When he approached the spot the machine had landed when he had gone back to 2008, he recognized something that looked like the house it had been in—not quite, but close. Sometime in the next twenty or so years, it appeared, additions would be made to the place. If the machine had gone to the same spot now that it had when he had taken it, he wouldn't be in someone's home, but rather… He peeked over the fence. Ah. He could just make out through the foliage a machine that looked exactly like the one he'd been using.

A loud screech interrupted his observation, and John whipped around at a deafening crash that seemed to have happened further down the street. He approached the road cautiously and…oh.

Oh.

From a distance, he could see two mangled vehicles, shattered glass strewn over the street and smoke rising from the scene. A head of dark hair rested against the airbag; a young man had been thrown halfway through the windshield. The driver of the other vehicle was running his hands through his hair, and appeared about five seconds from hyperventilating. They were almost certainly dead, but maybe he could—

From the corner of his eye, John glimpsed movement. Someone in the adjacent property was shuffling behind some bushes. Oh, a crash and now a robbery, lovely, he thought, keeping tabs on the figure in his peripheral vision while maintaining his gaze in the direction of the crash, trying to decide whether it was his place to uphold his oath and see if there was anything left to be saved there or—

A particularly noisy crashing sound returned his attention to the shady figure in the shrubbery, and when he looked over this time he could actually make out the person's face. It was a man who was—who looked—it was the man thrown through the windshield farther down the street. That, or his twin brother.

Andrew? It was one possible explanation—this time, in this place, a likely one.

John held up his hands and walked slowly toward the man. "Are you Andrew?" he whispered as he got nearer. He nodded toward the car crash. "And are you him?"

"Yeah," he exhaled a puff of air. "That's me. I guess you…well. You must somehow know about the machine."

"Your friend Brian sent me here to find out what happened to you," John said. "From 2012. He misses you."

"I'm sure he does," Brian said. "But I can't go back." He nodded toward the car crash. "That's me. That's going to be me, pretty soon." John's brows creased and he tilted his head, requesting an explanation. "I didn't think I would want to, the first time I saw it happen, but…it's going to. I know it." He glanced across the street. "I'm over there, too. And I'm in the house. I've tried to save her in a hundred different ways. Something always stops me."

John felt his heart drop six notches, dipping into his belly. "You…"

Andrew looked down at his hands. "I'm sure Brian told you why I built it. I came back here to save her. I can't. And maybe I'll try once or twice more, but I won't. One of these times, I'm going to decide to get in that car and die with her. You just saw it happen."

"You could still change it," John insisted. "Find the right—"

"I can't. It's already happened. I don't have a choice. Everything that's happened, has happened, and that's it." He took in a shaky breath. "The only thing you can decide about the past is whether you want to die in it. And I have—I will. And when I do, I'm going to send the machine back home, I suppose—I was thinking of doing it anyway, and now I know I will, because here you've used it."

John had recognized Brian's eyes when he came to John with the case: the eyes of a man who had lost his best friend. "Brian will miss you, you know. He seemed…distraught." A painfully obvious understatement, that was. Right, just a little bit distraught, just like me—

Andrew continued to look at his fingers. "I know. But I have to do this." He lifted his eyes to his body down the street. "I already have. And I—I don't think I regret it. She was—my wife was—well. Since the day she died I spent my life trying to be with her again. I suppose I finally will." John shuddered, imagined Sherlock falling, imagined two crunches on the pavement—"Tell Brian what you like," Andrew continued, eyes reddening. "Say I'm sorry I didn't leave a note. Say there was no way to stop me." His lips creased into a frown that was meant to restrain more. "Destroy that machine the moment you get to where you're going or he might try to come back and see. And he…he can't. He'll…" Andrew gulped down a lump.

But there was no way—there was no way. Absolutely, John thought, no way that this was true. Andrew hadn't tried hard enough, hadn't found the one thing that could set all the changes in motion. He gave up—he was going to give up. John wouldn't. He closed his eyes.

Sherlock spread his arms and fell forward—

No. No, that wasn't happening.

"You're here for someone, too, aren't you?" Andrew asked through a tight throat. "You didn't just come here for me." He looked John over. "Who are you? Why did Brian send you?" John opened his mouth, but Andrew continued speaking before he could explain. "Oh, I recognize you. You're—you're that detective bloke's blogger, aren't you? Watson. He thought you could investigate it for me, and you did. It's your friend, Sherlock Holmes, am I right?"

John could only nod.

"Jumped off a building, didn't he, just before the papers printed about him being a fake?"

"He's not a fake," John said through clenched teeth.

Andrew's gaze softened. "Oh," he muttered. "Oh."

"You don't believe me, do you? Of course not, it was in the papers, is that it? Well sod this, I—"

"I believe you," Andrew cut in. "I get it."

"Get what?"

"You want to stop him jumping," Andrew said. "Because you love him." John opened his mouth, shut it as Andrew continued. "You took the case because you thought you could use the machine, too, if it worked. You liked the idea of, like me, going back and saving the one person who mattered most to you."

John felt his nostrils flare as he took a few deep breaths to settle the burning that was threatening to run its way up his throat. "I'm going to kill Moriarty," was all he could manage to say. "Before all that mess."

Andrew started to speak, but couldn't seem to get words past his throat, and, after a time, gave up. He lifted his eyes to the crash, stared at his and his wife's dead bodies for a minute. "Go home," he finally murmured. "I know you think if you have enough will, if you feel it enough, you can stop it. I felt the same way, the first time and the second time and the third…" He looked to John imploringly. "But you can't. Go home."

I really don't have one without you, Sherlock, John thought. That's what you've done to me. "I can't."

"I have to go," Andrew said, and slunk around to the fence, toward his time machine. "I'm sorry, John."

John swallowed down the lump in his throat. His hand was shaking.

... ... ...

There were a thousand ways Andrew could have stopped it, John thought as he walked along the first street he'd ever walked down the first time he time traveled—briskly, briskly in the hopes that he could work the knots out of his guts, briskly because against all his medical knowledge something deeper and more driving was telling him that the only way to slow down the hot furnace in his chest that drove his heart was to wear it out.

But walking wasn't the way to wear one's heart out.

There were only two ways to do that: to cut it out (like Jim Moriarty, if he'd ever even had one in the first place) or to use it and use it and use it, to use it until it fell into pieces, to run it into the ground. To run it into the ground: run into the ground, like Sherlock. Sherlock had run his everything into the ground but John doubted it was for his heart, it was something else, there was something else that had driven him to do it and whatever it was, he'd stop it. But that's what John would do and he knew it, now, especially seeing Andrew: he'd use his heart for everything it had; he'd use it until it broke down and with any luck by then Sherlock would be there, and Sherlock had mysterious ways of bringing John to life.

There were a thousand ways Andrew could have stopped it that he didn't try, that he probably didn't try, that he probably didn't have the courage to try.

He could have gone back farther and stolen their car. He could have broken into their house the night before. He could have attacked himself and got himself sent to hospital and his wife would be there with him this morning, rather than in that car. He could have found the person who ran into her vehicle. He could have stolen his car. He could have stolen a different car and hit him two streets back.

John was going to kill Jim Moriarty. He was going to shoot him long before he'd ever become a problem. Not now, though—not now. Sherlock needed Carl Powers, he needed that to happen, needed that taste of detective work. Maybe Jim wasn't so bad yet—he was, of course, awful; he killed somebody—but then, John killed people—but not this young. No, Moriarty probably deserved it now, too—but that wouldn't be fair. And maybe, maybe John wanted to see a spark of recognition in his face before he died; maybe he wanted Moriarty to know that John killed him, that John killed him for Sherlock.

Sod what Andrew said. John would do it. Andrew just hadn't tried hard enough. Maybe what he felt for his wife wasn't enough to drive him to it: what was it, a simple romantic attachment? Something easy, something replicatable. John had loved four women in his life and he would never have gone this far to save any of them. Mary, maybe, Mary—no, not even Mary. He loved her dearly. He would travel back in time for her, and he would kill to save her—but he wasn't sure about both, because killing to save her in the past meant changing something important about the future, didn't it, and the future was precious and fragile and he met Sherlock on such a small, slight chance, and that was something he would never give up. Or would Sherlock still be alive if he and John had never met? No—no. He would have died by poison in 2010. He would have been kidnapped by a Chinese gang and shot. He would have been blinded by splashes and fumes of chemicals but for that John bought him a new pair of goggles; there were six other times he would have been shot; there were four times he may have starved to death and passed out god knows where; maybe he would have resumed smoking, maybe he would have gotten lung cancer; maybe he would have gone back to drugs if something took a bad turn.

Whatever else John would change by killing Moriarty, as long as he still met Sherlock, as long as he still had Sherlock, it was fine. It was all fine.

This wasn't the same as it was with Andrew. He just didn't try. He didn't have this burning furnace, or maybe he did but he used it all up making his machine and had run it all out by the time he got here. From 1989 to 2012, researching, building the machine, testing it, traveling back—that was a long time: maybe he forgot. Maybe it was possible for him to forget. John would do better.

"Be logical, John," said Sherlock-over-his-shoulder.

John shuddered. Don't we have something more important to be doing right now? he thought toward Sherlock stiffly.

... ... ...

Before John could do anything though, god, he needed a shower. On top of that, he hadn't even the slightest idea where he could find Moriarty. Could he look him up in a phone book? It seemed an odd idea—certainly, in John's present, such a thing was impossible, but he probably still lived with his parents—if he had those, anyway. Well: if they were still alive. But did he really have the same name, then?

He didn't have much of a lead besides that, though. It was anyone's guess what part of the city Moriarty lived in—it was anyone's guess whether he lived in the city at all, at this time. Probably, simply by virtue of having gone to school with Carl Powers…

Of course, there was Carl Powers, wasn't there? Carl Powers wasn't dead yet. John could look him up, find up what school he went to—but no, he was somewhere in Brighton, wasn't he? That was what Sherlock had gotten from the shoes. And if he went to the same school as Moriarty, then Moriarty wasn't in London, either, not unless he had the funds to randomly venture into the city. But then, the swim meet wasn't all that far off—John remembered the date on the article that Sherlock had pinned to his great mess of a bulletin board during the time that Moriarty played his five pips game with Sherlock. It was in early June.

"I wouldn't have expected you to have remembered the case," Sherlock had said to John as they hovered near the board. "You'd have been, what, about fourteen?"

"Around there, yeah."

"You had other things on your mind than murder and mystery, I'm sure."

John had puzzled over whether that was Sherlock's attempt to get John to talk about his past—about long before he and Sherlock met.

"Girls and football, I'd suppose," Sherlock said absently, tracing his fingers over the strings connecting his thumbtacks.

It wasn't entirely true: when John thought of being fourteen, he thought of Harry. It had been the beginning of a swooping downward spiral; it had been about when she really started drinking. It soured the taste of everything else that year, in that year before he was able to begin getting used to it, to that being the way things were. Every memory connected back to Harry then. He was assigned some Alka-Seltzer experiment for a science project; Harry took the tablets he was supposed to bring into school. He had a clarinet solo in the winter concert; his parents couldn't make it because Harry was in hospital. John's fingers had quivered through the solo, his overtired mouth not quite able to push breathy puffs of air past the reed (the fourth movement of Music for Prague 1968, the best piece they ever played, in John's opinion, while he was in the concert band). Better that he had missed the concert and somebody else taken the solo instead—but that was how it was. He made it through; the audience applauded; but all he could think about through the mayhem of the music was Harry.

"Toccata and Chorale," Sherlock had said, and snapped John out of his thoughts. At John's confused squint, Sherlock clarified, "That's what you were just muttering the rhythm to under your breath. The fourth movement of Music for Prague 1968. Well-known wind ensemble piece. Why?" Sherlock narrowed his eyes at John, thinking, calculating, and then slowly rotated back toward the bulletin board.

"Well, I—"

But Sherlock turned to grab John by the shoulders. "Prague—Czech!" he nearly shouted, and then began rearranging his thumbtacks.

"Right," John had said, and he went back to his chair and opened up his laptop to do what he could in helping Sherlock find out who was rigging all these people up with bombs, who had killed Carl Powers.

John remembered the date because it was what he was staring at when Sherlock, still unwinding twine and rethreading it, said, "I'm sure your rendition wasn't nearly as bad as you think it was." He'd considered asking how Sherlock knew—but it was probably something like his face while he muttered it, flinching where he'd erred, something like his fingers twitching in time with ghosts of clarinet fingerings.

"Thanks," he said instead, staring at the digital scan of an article dated the eighth of June, 1989. Eighth June, June eighth, six eight, sixty-eight. He resumed searching the page for details.

It was soon, then—less than a month off. How likely was it that Moriarty would commit a murder at a pool he'd never once scoped out before?

John could go there to check things out—maybe there would be some clue that he had been there. At the very least, he could get a shower at the same time. And at least the pool would be easy to find—it was, after all, impossible to forget.

He had never planned on paying admission to this particular pool. John thought about it as he entered the changing rooms—he had never really intended to go back. But that wasn't quite true: he had almost done so several times. He'd almost suggested it to Sherlock, but then held back. "Sentiment," Sherlock would say. (John's therapist would probably have said something else entirely.) For all that horror that had happened that night, John had left the pool with Sherlock feeling giddier than he'd thought possible. Yes, his legs were shaking; no, he didn't know quite what to say. What was it, when a sort of confession was forcefully pulled from both you and your flatmate, swiftly, unexpectedly and all at once? Not that he'd had any idea of what it might have been, at the time; and maybe it was going to happen for real, unprovoked, on the sofa later, before John made his stupid crack about Bond. It was a confession, though, John thought, from the both of them, from the way their eyes locked, from John's grabbing Moriarty from behind and Sherlock's solemn eyes whenever he looked at the glowing red dots on John's chest. It was a confession: it said, You're something more.

But after Sherlock's—after Sherlock was gone, John couldn't bring himself to it. What was it? Not really anything besides a reminder of something that John would never be able to relive, would never be able to explore. But now—now it was different. John was going to save Sherlock, and maybe the first thing they'd do would be to return to the pool. "Let's do this over," John would say, and shrug on a coat, and wait, and see what Sherlock did.

John stripped his clothes off and piled them up outside the showers, taking special care to hide his gun inside his jacket. If nothing else, he could come out of this not smelling quite so bloody terrible, even if he did have to use that godawful cheap public shower soap. Meanwhile, as he scrubbed off as best he could, he tried to tune his ears in to the voices around him—a couple of old men who'd just finished their laps, discussing lunch plans; one bloke whistling to himself.

"—and stop calling me Jimmy," said another voice. John froze.

His thoughts followed a progression approximating:

That's him.

My gun is with my clothes.

No, I'm not going to shoot him.

My gun is with my clothes.

No, he's not going to find it and shoot me.

My gun is with my clothes.

He was close enough to being done anyway; he dashed from the shower and patted the majority of the water off of him with his jumper before yanking his clothes back on. The jumper could dry out while he wore it. John peeked furtively around a corner to the lockers, tucking his gun back into the back of his trousers and covering it with his jacket.

Moriarty was hunched over, sneering at the man beside him.

"You never had a problem with it before," said the man, and now that John could see his profile, he was sure of it: this bloke was related to Moriarty somehow.

Moriarty—Jimmy—dropped the bag he was carrying. "You're mistaking fourteen with four, father," he answered drily, staring at the bag with scorn.

"So I'm supposing you don't like swimming now, either—"

"No."

"—Jimmy, you used to be such a nor…such a reasonable boy," said the man—Jimmy's father. John tried not to stare too intently, to decipher what kind of person could have parented someone who grew up to be the monster Moriarty was. Was it an accident? Did Jim's father, too, run some sort of crime ring? From several locker rows away John could detect little about him. Tired eyes, premature wrinkles—those could come from anything from a genetic predisposition to a tough life to a drug habit.

Moriarty—Jim—apparently had no answer for his father.

"You love swimming—have you forgotten? Come on," he insisted, and John shifted his eyes away politely as the man changed into swimming garb. He straightened up his jumper and made his way over to one of the restroom stalls, ducking in but keeping an ear on the exchange.

John could hear Jim kick at his bag. "You can't make me."

"No," answered his father, "but your mum probably won't be too pleased if she hears you didn't get any exercise all weekend."

"As if you've ever cared whether she's pleased," Jim answered sharply. "Sod the both of you. You know how often she asks after what I did while I was here?"

Silence.

"Get your swimming shorts on." It came out as a low growl; John shivered to himself. He was reminded of a colonel he'd served with for a few months.

Jim, apparently, complied; when John exited the stall a minute later, they were both dressed to swim. John washed his hands, watching them through the mirror.

"Now this is nice," said Jim's father. If Jim's icy features were any indication, he disagreed strongly. "I hear some of your mates from school are going to be up here swimming next month," he continued, picking up his towel. He tossed another to Jim, who let it hit him and then crumple to his feet. "Guess we'll have to come cheer 'em on, won't we?"

If John had blinked, he would have missed it—Jim Moriarty's face, several seconds after his father spoke.

Before death, John thought, some peoples' lives flashed before their eyes: but that was just the most obvious side of a coin. He supposed it meant something good for humanity, that the other was not a common phrase, a well-known phenomenon.

John knew it, though. He'd seen it a hundred times.

Before one died, or maybe just when one almost died, he would be frozen—or feel frozen, brain in overdrive—as memories or feelings or ideas flooded through the brain and then the body, maybe one last time. That person would come the closest he ever could to understanding the meaning of life—however much or little that was.

What John saw, what John had seen a hundred times before, was the opposite: the slowly dawning and then consuming realization of the ability to take life, not as an abstract thought experiment, but in grasping that one could do such a thing, at any time, under his own power. There was something inherently maddening about knowing, knowing that any person nearby was also just one blinking realization away from being a killing machine, under the right conditions, with the right provocation, whether by brute force or planning: anyone could kill. And in this sweeping realization, this dawning of an unerasable shade of terror on one's heart, lived the primal knowledge of the meaning of death.

("You have just killed a man," Sherlock said, on the second day they knew each other.

"Yes," John had said. "I know." The meaning of death wasn't much: it was as empty as the fate of dying itself, the mathematical complement to life as everything.)

But that wasn't the whole of it: that wasn't the meaning of dying.

Children, John thought, are incapable of understanding death—and then the moment finally comes, the knowledge and acceptance of not-coming-back. Some adults revert to the state of unknowing: some, for a lifetime. (John was still surprised when he checked his mobile and found no smartarse texts about typos Sherlock had found in his blog. John was still surprised when he stayed a night at 221B and heard no violin.) There is a second level, too, though: one most never need to reach, or not quite so young, anyway—understanding dying.

John had watched life leave bodies more times than he wanted to count. He had caused life to leave bodies a fair few times, too. What John saw on Jim's face through the mirror was transcendence to this level, the monumental shift from death as a thing that happens to people to a thing people do, to an act in and of itself, from could happen to can happen. John had seen it on men who pulled a trigger and watched a target fall; he had seen it on doctors under whose own hands life, sometimes violently and messily, actively, not passively, left a body. John was sure someone else had seen it on him: years ago, lifetimes ago. Or, since right now it was 1989: perhaps less than ten years from now. He could watch it on himself, were he so inclined—but he wasn't.

John knew for Sherlock it had happened much later; John had seen it himself, or the end of it. He envisioned, but could not know for certain, that the first turn of the first cog was at the faint click of the trigger of a landmine. Whenever it had happened, after Dr. Robert Frankland was blown into a thousand pieces and the light began to fade, Sherlock had turned to John, John, who could only think god, not again, not again until he saw Sherlock's face: god, not you, not you. Of course it was inevitable for Sherlock: of course. Surprising, maybe, that it had not happened already (or not: Sherlock dealt with the dead, the then, the aftermath). But the panic in Sherlock's eyes had flickered over John like strobing light, and John had wanted nothing more than to grab Sherlock by the shoulders and shake the machine out of its turning, take dying away from Sherlock and leave him to what he was best at, death and life and living, while John could take the dying, because he could take it.

("You have just killed a man."

"Yes. I know.")

He could take it until a point, anyway—until the dying was Sherlock's.

What John saw on Jim Moriarty's face through the mirror was this transcendence, was this realization, and it was not at all like Sherlock's panicked haze.

For a half a second, Jim smirked.

John turned away from the mirror to dry his hands.

"We will," Jim agreed, picking the towel up from around his feet and slinging it over his shoulder with what ought to have been an amicable smile at his father. "We'll have to do just that."

"You like your school there? Got some friends?"
John watched a distasteful sneer pass over Jim's face before he answered with a nonchalant, "Some."

"That's good. Friends are good. That Newcomb chap still bother you about copying homework?" Jim's father seemed proud of himself for remembering that small detail.

"No."

"Oh. Good."

"Very."

"Yeah." He reached for his towel and tucked it under his arm. "Don't suppose you've got yourself a girlfriend yet?" John winced at this: it was more an accusation than anything else. To John's surprise, Jim winced, too.

"Yes, wouldn't want me to focus on academia, would we?" Jim finally said, apparently recovering some sharpness as he spoke. John had to hold back a wry laugh, had to avoid clearing his voice and pointing out that all Jim was thinking about right now, as of about twenty seconds ago, was murder—murder and crime, maybe petty, maybe selling answers or bribing teachers with threats of I know who you're screwing in the lounge during fourth period, but not for long—soon it would be hiring homicidal cabbies and bombing five floors of flats and framing fucking Sherlock Holmes as a fake. Jim Moriarty wasn't focusing on academia; probably, probably he was building his web already, its very beginnings. "Friends," he'd said he had, but Moriarty definitely didn't have friends. John would bet money on what kind of friends they'd be. Sherlock had no friends, or so John had been led to believe; Moriarty had "friends," which, John thought, from the distaste on Jim's face as it was brought up, meant things like people he used to get things he needed. When bullies laughed at Jim, maybe he had someone to turn against them, with his slithering fist twisted around so many wrists, tugging them with blackmail or worse after drawing them in with lies and an amicable smile; Sherlock had probably had no such luxury and no such power. Sherlock walked home and got beat up by sixth form arseholes and, rather than lashing out, seemed to pretend it hadn't happened, wasn't important. Perhaps he truly didn't care, or perhaps he internalized the insults. Jim Moriarty, with the flicker of realization through his eyes, with the sudden drive to kill, like today, like right now, at this age, was more…reactive. After a pause, Jim added, "Suppose I ought to get to finding some prissy bitch to knock up instead of going to university, oughtn't I?"

John turned away from the mirror at the deliberate flex of Jim's father's jaw, at the ball of his fist, at the way his eyes darted around the locker room.

"You know what, though," Jim spoke again, his voice higher, this time, brighter, as he threw his towel over his shoulder and took off toward the doorway to the pool, and that shift of that voice in the echoes of this pool made John shudder, "I do know one of the blokes swimming in that competition next month…"

Jim's father breathed, John could hear, slowly, for several seconds, before following his son. "Do you?"

"He's in my maths class…" was the extent of what John heard, and the extent of what he would hear unless he wanted to risk walking out into the pool area fully clothed without being noticed. Probably a bad idea: god knew what would happen if Jim saw and recognized him years later.

John sighed and sat back down on one of the benches, leaning back to rest his head against the wall. Jim Moriarty—he shouldn't, of course, be surprised by the idea of Moriarty with a family (in whatever state it was in). Sherlock, after all, had his own family, had been a child, was about to begin becoming a detective, soon, after Moriarty killed Carl Powers. All this time—Moriarty, with his spark of the knowledge of dying, slowly turning London, the world, whatever he touched, to chaos (or maybe, John thought, to order, a well-oiled machine), committing the crimes and inciting the crimes and funding the crimes that Sherlock would solve—some of the crimes that Sherlock would solve, at least—making him, and then unmaking him. Not that Sherlock could be unmade—he could never be unmade. John would make sure of it.

That was why he was here, wasn't it? He would have done so either way—would've continued insisting that his stories were the truth, that Sherlock Holmes was real; maybe it would be just him and a handful of others, in the end, but if it came to it, if John was the only one left who knew that Sherlock wasn't, was never, a fake, it would burn on inside him. He could donate his chest cavity to the truth, make it Sherlock's. Could a mind palace fit inside one's lungs?

"Don't be stupid," he heard Sherlock-over-his shoulder mutter. John felt a tug in his heart.

Maybe there was a point in Jim Moriarty's life when he had been different, but even this young, John could see that he was little more than a miniaturized version of his future self, already working his way up to the monster he would become.

But he wasn't a murderer yet, imminent though it was.

He was other things, though, John suspected. A premeditated murder like Carl's death seemed like it would require some working-up to. What was Jim already doing? John found he didn't care to find out the details, based on what he'd already seen; and it hardly mattered, now. Doubtless he was already manipulating people, learning how to feign expressions and how to lie and get away with it. John tilted his head forward, resting it in his hands as he thought.

Sherlock did the same thing, though, didn't he? Like a switch, three seconds into a sob story and weeping already, and then before John could process what was going on, was striding away with the facts in his brain and deductions rattling along, funneled through John's ear as he followed. It helped having someone to talk to, Sherlock had said—but so far as John could tell, and based on anything anyone had said to him before—

("You know him better than I do," John had said to Lestrade, and,

"I've known him for five years, and no, I don't," said Lestrade.)

—Sherlock had never had anyone to talk to; not like that, anyway. How would he know?

But he did it all the same, once John was there, and John was all in before he'd even known it, had spent all of a day between potential flatmate and friend and assistant. Sherlock had started introducing him as a friend so very early on, for a man who didn't seem to have any friends. John didn't mind (though he tried correcting it a few times, trying on different hats, seeing what felt better, and yes, in the end, friend was so much better than colleague)—it felt, oddly, perfectly natural, as if he and Sherlock were two souls picking up where they left off in a previous life. Maybe they were, maybe that was why Sherlock was so fantastic, maybe that was why John was time-traveling to save him. Maybe they had known each other for a hundred years. Maybe time was no object. After this? John would believe it. He'd believe any of it. He'd go back a hundred years and over his shoulder he'd hear, "Pass me that tobacco sample, would you?" like nothing had changed.

And that was one thing that Sherlock was that Moriarty wasn't: real. Himself. Always. When he acted, when he flipped the switch and wept, he stopped as soon as he got the information he needed, as soon as the cogs were unstuck and churning again. "I see. Thank you," he'd say, maybe a bit coldly, to a very confused wife or husband or child or friend, and that was that, and he was Sherlock again. No games—never games. Only, John could imagine Sherlock saying, the Work. Sometimes it was a game, and a game he relished, but Sherlock navigated through it like the protagonist of a novel, the lens of truth, the only honest and reliable voice. When he lied, when he deceived, he took off his hat at the end and bowed while the police made the arrest. He told the victim of his deception: "See? That's not me at all. You've been fooled, but it's fine, because I'm Sherlock Holmes, and the world is a better place because for two minutes you thought I was someone I wasn't."

John was waiting to hear it; but maybe he never would. He hadn't, after all, been fooled. If Sherlock had stayed on that rooftop for a minute more, would he have extracted what he needed, would he have found the solution and laughed into his mobile and said, "You know that's not true, John, but thanks for playing along, I've figured out how to fix it now"? He'd step away from the ledge and John would rush into the hospital, and they'd meet in the stairwell or the lift—and then what? God. Anything. Anything that happened then would be better.

But Moriarty—who knew who the real Moriarty was? A bundle of misconceptions and layers of disguises, disguises that meant something and disguises that didn't, some that came off and some that stayed on. When he spoke in singsong, was that him? When his voice became hard and sober, was that the singsong falling off, or being covered up, or both, or neither? Moriarty left the stage exactly as he came on, and never emerged for the final bow smiling, out of character, back to himself; he never emerged for the final bow. Whatever had happened to Moriarty, he had not stepped forward to claim credit for the final act. (If that's what it was, and that had to be what it was, didn't it?)

Maybe what John had seen now was as real and pure and true as Jim got; it probably was. Feelings still peeked through; he was still, at least, a human. This was sometime before he had buried that inconvenience. Sherlock, for all he complained about people and their people habits and the inconvenience of humanity, Sherlock masked his own under only a thin layer, for protection more than anything. What else could he do, being called freak on a daily basis? (Probably, John thought, Jim Moriarty was, too. Maybe that was how it started; maybe they diverged because Sherlock had a more understanding family; maybe the simple fact was that Sherlock was good, or at least not-bad, and Jim was not-good, was bad. Sherlock might have poisoned animals out of curiosity; Sherlock never poisoned classmates out of spite.)

Sherlock seemed confident he could shed his humanity, but John knew, and he assumed Sherlock knew, too, that while Sherlock was so fantastic and extraordinary and unbelievable he was also human. When John met him he was the first three of these; and then Sherlock had tricked John's body out of its limp, and then the door to 221B shut and they laughed, and then John shot a man and Sherlock watched John feign innocence, aglow with awe, and they giggled. They went to a Chinese restaurant; John watched Sherlock order hot and sour and slurp it, flecks of it landing on Sherlock's cheeks and fingers. Sherlock became, suddenly, human—more human than anyone. He looked up at John through shy eyes and every layer, every scrap of his showiness and his preening and pride (equally honest, and, true, rightly deserved) had fallen away. When John thought about it now, Sherlock had looked a bit like a child, like the Sherlock he'd just seen not so long ago, unsure and so surprised by someone sitting across from him, willingly basking in his talents and in the quiet, silvery light that emanated from those crystalline eyes, willingly sharing his company.

Sherlock liked having someone to talk to, and that's what John was for him. That's what John had been for him, too, when he had visited him, now (then), in his childhood. And god, he hoped it made a difference—whatever sliver of a difference there needed to be, to calm Sherlock's tears from the rooftop (were they tears flipped on like a switch? That, John thought, might be worse), to make him breathe and step back and know, know, that whatever he needed to do, why-ever he needed to do it, John could help him, they could make it together. He was worth so much more than whatever the hell had made him jump.

Maybe, John thought, he had made a difference. How would it change Sherlock? God. Maybe Sherlock would take a completely different path, would never meet John. Maybe John hoped Sherlock hadn't changed at all.

The fantastic thing about time, though, about time being no object, for him, was that he could travel through it, and see. He could make sure. He could watch. Maybe later, maybe in university—maybe Sherlock's days would be a bit less rough; maybe he'd stayed away from drugs, or quit sooner, or used lighter. Maybe arseholes like Sebastian Wilkes didn't hate him, or maybe, if they did, Sherlock's eyes wouldn't flit down guiltily, would instead shine with a bit more resilience as he held his head up and continued on doing what he did best.

John could go to sometime before the second time Mycroft saw him, to avoid him meddling; he wouldn't be looking for John then. Mummy Holmes would, it appeared, keep John and his machine safe. He could just…check up on Sherlock. Make sure he was doing okay, maybe doing better. He could make sure he hadn't messed anything up too badly. He could check on Sherlock, and then he would do it, he'd do what Andrew couldn't do, and save Sherlock. Couldn't he? If Andrew was right, he couldn't change a thing—Sherlock would jump no matter what, no matter if he seemed better off, happier, more at peace with himself, or not. If Andrew was right, maybe John couldn't have helped him at all, that one time, speaking to him in his childhood—like Andrew trying to stop the car crash that happened every time. If Andrew was right, Sherlock would jump either way—but Andrew wasn't right; Andrew hadn't tried hard enough; John would save Sherlock. He'd find Moriarty, after the pool, after going back to the flat, after Sherlock had looked to John with the same painfully human eyes and almost said something so important. John would kill Moriarty, would find Sherlock, would wrap his arms around him and maybe break his ribs a little in the process.

"What was it going to be?" he'd ask. "What were you going to say?"

And Sherlock would say it, and whatever it was, John would be grateful. He'd let Sherlock go slowly, feel Sherlock's ribs expand back into place. Sherlock would say it, and John would nod, and from there—from there the mystery and the adrenaline and the adventure would start again, because Sherlock would be as safe as Sherlock ever was.