Warning: This story contains implied rape. Nothing graphic, and neither Sherlock nor John are the target.

I owe a huge thanks to mustangwoman for suggesting I do something more with Sam. I didn't expect it to turn out quite this way, and I am incredibly happy with it. Thank you.

The livingroom was a disaster. Most of the flat was. Equipment for all manner of experiments was strewn about, as well as books, old newspapers that had earned a panicked "don't touch those!" when John had attempted to recycle them, and several mysterious vials the doctor suspected were biohazardous and didn't want to handle. He felt as if he'd walked into an explosion on some science fiction set, but when he tried to tidy, Sherlock got antsy and followed him around, taking things back down from where John put them away.

John had declared the bedroom off limits, so Sherlock had shunted the mess to the spare bedroom upstairs, the one that had been John's a little less than two years previous. John learned where to step and not to step, so he could now trace a hazard-free path to the loo in the middle of the night. He still had a fading bruise on one shin from something in the hallway that he'd never identified. It was gone the next morning before he got up and Sherlock wouldn't answer any questions about it. He was very generous at providing ice packs for the bruise, though, as well as at least one sympathetic look.

John took what he could get.

He wished Lestrade would call. He toyed with the idea of calling the detective inspector himself and pleading – it was almost to the point of pleading. Sherlock was very clearly getting bored; he wasn't shooting holes in the wall anymore, because he'd given that up some time ago. Now he relied on John as a source of boredom relief, which was generally fine with the doctor, but not when he was at work.

Whatever toys – although John never called them toys aloud – Sherlock needed were therefore tolerated.

Except that, for the past couple of days, when John came home, the mess was clearly untouched, because nothing had been moved, discarded, or set on fire, and Sherlock was perched in a chair, intent on his laptop. John had no idea what Sherlock was working on, because his husband evaded any questions, and John knew better than to press for details. Eventually, Sherlock would start to want to tell him, and if John held out long enough, he'd get all of the information he wanted when Sherlock solved whatever little puzzle he was sorting through and needed desperately explain it to someone.

The day that happened, John came home and wished their flat had some kind of air conditioning. It was stifling outside in the August heat, but nothing compared to the oppression inside the Baker Street flat. Sherlock's curls were matted to his forehead, but otherwise, he didn't seem to notice. He was wearing a dark t-shirt that John was certain belonged to him, because it was slightly too big for the lanky detective, and jeans. John loved when Sherlock wore jeans, and said so as much as possible. The fact that his husband was wearing them meant that Sherlock specifically wanted John to be distracted by how he looked.

John wondered about his mental stability that he could tell that. Three years ago, even two, would he have thought that? But then, even two years ago, Sherlock had still been just his flatmate and his clothing had made no difference.

"Look at this," he ordered as soon as John was through the door and spun his laptop round toward the doctor. John signalled for him to wait and Sherlock made an impatient noise, so the doctor took his time removing his shoes.

"I need to change and shower," he said.

"This is important!" Sherlock said.

"We need to buy a fan, or an air conditioning unit," John said, pretending not to have heard. "It's terrible in here."

Sherlock stared at him, then gave a hearty huff. John grinned, crossing the livingroom.

"Hello, John, nice to see you," he said. "Have a good day, then? I missed you. How about dinner out, so we can sit somewhere cool?"

Sherlock rolled his eyes, absently brushing his damp hair from his forehead.

"Yes, all those things, but look," he tapped the laptop impatiently with a long index finger.

John sighed and kissed Sherlock quickly, then looked at the screen.

A police record stared back at him. Not an arrest record, but a personnel file. The kind that was highly confidential, and difficult to obtain. At least, difficult for most people. John closed his eyes momentarily, as if being unable to see the file might make him less complicit in this.

The picture of a young constable grinned back at him. John recognized Sam Waters, or, as he'd begun to call him, "that constable you fancy", whenever he came up in conversation, which admittedly wasn't very often. The bulky nickname drove Sherlock crazy, which made John use it all the more. He wasn't really worried about it, but he enjoyed seeing Sherlock ply him with reassurances. Sometimes, you took your fun where you found it.

"Sherlock, why've you got Sam Waters' file? Do I even want to know?"

"Read it," Sherlock insisted.

Reluctantly, John did so. It wasn't all that revealing, thankfully. Samuel Carroll Waters, age twenty-five, born June third, 1987, in Birmingham to Eugenie Carroll Waters and Samuel Henry Waters. It had his address, his private phone number, emergency contacts, all the usual information.

John gave Sherlock a look, but Sherlock returned it with a Look, and John sighed and kept reading. This was the full file, listing everything Waters had done that was pertinent to the police; his training records and graduation information, arrest records, his court appearances, his transfer from the Westminster area station to New Scotland Yard in late April of 2010, the names and ID numbers of his police partners, commendations and notes, etc. John felt like he was violating the younger man's privacy, which, point in fact, he was. This information wasn't supposed to get out to just anyone, and John knew Lestrade would probably have a coronary if he found out Sherlock had accessed it.

"All right, yes," John said. "I've read it."

Sherlock was practically vibrating with excitement.

"And?" he pressed.

"And?" John asked. "And nothing. It looks fine to me. Normal, I would imagine, for a bobby his age."

Sherlock gave a disgusted sigh, accompanied by a pointed look that John had long ago grown used to.

"Don't you see any mistakes?" he asked, gesturing impatiently at the screen.

John shook his head.

"No," he said. "But this is the first – and only – police personnel file I've ever read."

Sherlock blinked.

"You've not read mine? I'll make sure to get it for you."

"Sherlock, I don't want-" John started and then gave up with a sigh. "Right, just tell me. What's wrong with it?"

"Nothing!" Sherlock said triumphantly.

John blinked, then pinched the bridge of his nose.

"So you hacked into his personnel file, stole police property, invaded his privacy, for nothing?"

"No, John, not for nothing. Nothing is wrong with the file. That's what's wrong with it. Don't you see? Data entry people make mistakes – lack of attention, errors in transcription, typos, et cetera. Your service file is full of small errors, nothing that would be worth correcting, you see? The wrong time jotted down here, the name of your platoon misspelled there, all mistakes that don't matter."

"Wait, back up," John said sharply. "You have my service records? How the bloody hell did you get my service records? And since when?"

Sherlock gave him another long look, grey eyes cool.

"Since three days after I met you. It wasn't difficult. Well, a bit of a challenge, since it took three days, but admittedly we were working a case, so I couldn't put as much time into it as needed."

John groaned, sinking onto the arm of the couch.

"Sherlock, if the army ever found out-"

"They won't," Sherlock assured him with unflappable certainty. John let out a sigh, but had to admit to himself that his husband was undoubtedly right – first, Sherlock knew how to cover his tracks, second, he'd had the file for almost three years now, and they hadn't caught on.

"So Sam Waters' file is fine," he said, waving a hand vaguely. "Someone paid more attention doing the work. It wasn't Friday afternoon when it was updated. What of it?"

"It's not just one person, John, it's many people. Someone would make a mistake. Which means someone is doing a very good job making sure that it's flawless."

"And who would do that?" John asked, starting to feel a little slighted at how much attention Sam Waters was drawing from Sherlock. Then he reminded himself the detective had stolen his army service records. Was it insane that he even considered that to be somewhat romantic? Probably, he decided. "And why? He's just a police constable."

"I don't know yet," Sherlock replied. "But look at when he was transferred into the Yard."

"Yes, I saw," John replied. "What of it?"

"Two weeks after The Pool."

John wondered if it was a bad sign that so many of the events in Sherlock's professional life ended up as capitalized titles in both of their minds. He frowned; he did not like to think about The Pool. Having a bomb strapped to you was not a happy memory. He'd seen more than one person go out that way in Afghanistan.

"So?" John said. "How many others were transferred in during that time?"

"I checked," Sherlock said promptly and ignored John's muttered "of course you did" reply. "Three others to Lestrade's command."

"And are they on your watch list, too?" John asked dryly.

"No, I checked and their files are normal," Sherlock replied.

"Sherlock, it's a coincidence. Officers get moved between boroughs all the time. Especially junior ones like him. Lestrade has a lot of people working for him, including a file-thieving consulting detective, I might add. He'd have your head if he ever realized you'd done this."

Sherlock ignored that.

"A man walks down a London street and bumps into a woman he went to school with in his childhood in another part of the country. That's a coincidence," Sherlock said. "A doctor returns from Afghanistan and wants to move to the city, but can't afford to. He meets up with a friend who has another friend who is looking for a flatmate, in said city. That's a coincidence."

John rolled his eyes, but privately thought it was one of the best coincidences that had happened to him.

"Life is made up of coincidences," Sherlock continued. "There are too many people in the world for it not to be. But this isn't."

"And why not?" John asked.

"Have you not been paying attention? A young man with a perfect file – not a perfect record, mind you, but close to – is transferred in to Lestrade's command within two weeks of the incident at the pool with Moriarty."

John crossed his arms and leaned forward somewhat.

"You're reading far too much into this," he said. "You're starting to sound like your brother." He ignored the look of displeasure that crossed Sherlock's face at that.

"He dyes his hair," Sherlock said.

"What? Mycroft?"

"Sam Waters, John!" Sherlock admonished. "He smells of shampoo designed for hair that's chemically treated, which means he takes care of it, but he never has naturally coloured roots exposed, nor does he had dye patches on his scalp, which means it's professionally done. His skin tone is also a shade too fair for the colour of his hair. Men with dark hair and pale skin usually have very visible five-o'clock shadow, but he doesn't, suggesting his facial hair is lighter, and therefore the rest of his hair is, too. Granted, most men have facial hair a slightly different shade than the hair on their heads, but not so drastic, particularly men with dark hair."

"You're smelling his hair?" John said, getting hung up on what he considered the important point.

"No, of course not," Sherlock said. "I can smell his shampoo when he goes by. We do work together, you know."

"So maybe he's going grey early," John sighed.

"He's not a vain man by other standards," Sherlock continued, shaking his head. "He uses expensive shampoo, but not conditioner – his scalp is dry – and cheap soap. He doesn't wear cologne, either."

John sighed again.

"Maybe he has a girlfriend who likes his hair darker."

"No girlfriend, or boyfriend, either. He's bisexual." At this, John raised an eyebrow. "No cologne. Nothing that is targeted specifically at one sex. And he interacts with men and women in a very similar manner. Single, but either unhappy about it, or unwilling to change it, because he makes no effort to alter his smell. Nor does he ever smell like anyone else, so no partner. No different deodorant or shampoo or even a touch of perfume. I smell like you, and you like me, because at very least we share the same bed, even if we weren't to touch or share clothing." As if to bring home his point, he tugged lightly on the shirt of John's that he was wearing. "So his hair is unexplained."

"You're not convincing me," John said.

"Also, his file's been altered."

At this, John started.

"What?"

"I did some more digging – you really didn't think it took me three days to access his file, did you? You can't tell on first blush, or even second or third, but it's there. I can't tell what information has been changed, because whoever is doing this is very good at covering their tracks. Here, look."

John looked, and Sherlock tried to explain, but gave up in the face of John's blank incomprehension. Medicine and all of its workings made sense, but he left the tech – and the insane ability for detail and pattern recognition – to his husband. But he had to admit Sherlock had a more convincing case being able to identify unknown alterations to Waters' file.

"So maybe he's undercover, or has been," John suggested.

"My thoughts exactly," Sherlock said. "But I should have been able to access that information as well."

John groaned again, dropping his head into his hands.

"What?" Sherlock asked. "It's not as though I'd do anything with it."

John only shook his head, heaving a sigh. Sherlock ignored him and picked up his phone, darting off a quick text message.

"And what was that?" John asked.

"For Mycroft," Sherlock replied with an evil glint in his eye. "If he put Waters there, then he'll pull him out now that he knows I'm onto him. If not, he can give us information."

"Us?" John asked.

"Of course," Sherlock said, looking somewhat puzzled. "Why not?"

John's lips twitched wryly and he gestured vaguely at the screen, then ran a hand over his mouth. Waters smiled brightly from his photo and John fought off a scowl. The young man was certainly striking, with an unusual combination of dark hair and green eyes. It seemed like a mix of coastal Irish and inland Scottish, only he was from the middle of England.

Sherlock glanced at the file, then back at John. He tilted his head slightly and then his grey eyes lit up, followed by a mischievous smile tugging at his lips. John felt himself redden slightly, against his will.

"John, are you jealous?" Sherlock asked slyly.

"No!" John protested. "I just don't think you should meddle with police files!"

Sherlock grinned wickedly and snapped the laptop shut without ever taking his eyes from his husband. He rose, stepping over to John, looking down at him with unconcealed amusement.

"You are," he said, his grin spreading.

"No," John protested again.

"Yes," Sherlock said, leaning down, putting his hands on the arm of the couch on either side of John. He closed the distance between them so that John could feel Sherlock's warm breath on his lips, see the small beads of sweat that clung to his forehead. He leaned forward in reply, almost groaning when Sherlock pulled back.

"John is jealous," Sherlock murmured, then bent in again, catching John's lips with his own, nipping John's lower lip lightly and chuckling at the response it elicited. "Let's see what we can do about that, shall we?"