A/N: So because of the fact that I was rewatching BBC Sherlock, I realized there were a lot of parallels between the characters in that universe and in Doctor Who (thanks Moffat), specifically in the Eleventh Doctor + Ponds era. You can't swap out every character in Sherlock with a character in Doctor Who perfectly, but it's close enough for me to be able to write an AU fanfic about it. So, Sherlock is the eleventh Doctor, and John is Rory. It won't be a direct retelling of Sherlock (I'll be adding a lot of my own plot points to it), but it will borrow some ideas from both shows. That being said, no characters from Sherlock will appear, so you won't need to have watched it to understand this fanfic. Hope you enjoy!

THE SCIENCE OF DEDUCTION

Hello, I'm the Doctor, and I'm a professional puzzle-solver, the only one in the world. I say puzzle-solver because that's what it is, I solve puzzles that nobody else can solve, but the police like to call me a detective. I don't quite know why. A detective implies that I solve crimes for a living, and really I do it as a sort of hobby. How else do people pass the time?

I doubt you lot would be able to keep up if I tried to explain what exactly I do, so I'll give you the simplest explanation possible. I look at things and make connections, a lot like finding just the right plug that would fit in just the right power outlet in a room full of different plugs and power outlets, or just the right hat that would go with just the right bow tie in a giant wardrobe of millions of hats and bow ties. Well, it's a bit like that. Okay, it's not like that at all, but that's not important. Is it? You tell me.

If you have a puzzle you want me to solve, or a crime you want me to investigate, whichever keeps your boat afloat, feel free to contact me and we can discuss your case.

The Doctor

Professional Puzzle-Solver and Consulting Detective

The man gently lowered the lid of the laptop, smiling to himself.

There had not been a day he hadn't checked the website. Since it was first set up all those years ago, he had had an eye on it. In fact, he always had a tab opened to it on his private computer. He was notified of any updates, and notified of any lack of updates. He knew of every time the Doctor had taken on a case: the successes, the failures, the kinds of people he dealt with and captured, everyone he had made his enemy or his friend throughout (one much more abundant than the other), his location, and any changes to them. One could say he was a fanatic. But he was much more than that - he loved the Doctor, but he had an insatiable hatred for him.

So he was ready when the Doctor was thrown out of his flat for drilling holes into the walls clear into the next room, and when somebody new moved in with him in a brand new place. In fact, he had something planned for this occasion - something he had been anticipating for quite a while now.

It was finally time to be introduced.

And it was thus that he took a phone out from a drawer, beginning to dial the number of a certain cab driver...

A Few Weeks Before

Clara, he wasn't surprised to see. It had been a few hours since the school day had ended, so he had figured she would pop around after grading tests to say hi, maybe introduce him some new baking creation of hers (her souffles were coming along, to say in the least). But it wasn't a new platter she was dragging along this time. Rather, it was a person - which was surprising, considering what had happened to her last boyfriend.

On second thought, 'boyfriend' could be eliminated. He was definitely not a new boyfriend - it was obvious right from the start, when he walked into the room, by his awkward gait and the way he trailed after Clara like they didn't know each other (he suspected that was the case here, which added a bit to the strangeness). Taking a cursory glance - eyes flicked up and down quickly - he saw a nose. A quite brilliant nose. It was one hell of a beak, right-smack in the middle of his face, between round and extremely nervous-looking blue eyes whose gaze roamed the room with a sense of displacement. Above the eyes was a fringe of close-cropped brown hair. He looked bewildered.

After a moment, the stranger's gaze landed on him, where it ultimately stayed fixed onto, perhaps because the Doctor was staring at him rather intently by this point. Many things had come to mind, half of which were immediately discarded and the other half kept circulating in the back of his mind. One thing had become rather clear to him, however.

He was his new flatmate.

Or rather, he could be his new flatmate.

Eyes narrowed, sending a quick sideways glance to Clara (who wore a decidedly smug smile that she was trying hard to disguise as not-smug, and failing very badly at), and then back at the stranger in question. The Doctor smiled despite himself, taking a few steps closer and clapping his hands down on his shoulders.

Mr. Potential Flatmate stiffened.

Taking a closer look, he could see several different things, all pointing to the same conclusion. The way his clothes were wrinkled, obviously saying they had been stuffed in a bag in a hurry, the stiff tangles of his shoelaces - suggesting he never unties them when he takes them off, possibly because of time constraints - a job that required quite a lot of hours, perhaps - amateur at shaving with a razor, but careful since he didn't have any recent nicks on his face - right, right, right.

How unique, the Doctor thought to himself with amusement. His attention focused back to his face, and he quirked another smile, smoothing the edges of his jacket down. "Royal Hope or St. Mary's?" he offered by way of conversation.

Mr. Potential Flatmate blinked again. He leaned back slightly, uncomfortable, and still with that same bewilderness which seemed to have only increased since entering. "...I'm sorry, what?"

"Royal Hope or St. Mary's?" the Doctor repeated. There was a pause, in which he still looked slightly unsure, so he delved into a bit of exposition. "The hospital you used to work at. You're clearly a nurse. A male nurse. Male." He turned to Clara, grinning like a madman. "Can you believe that? Less than fifteen percent of the entire workforce is male."

"Right?" she agreed with great enthusiasm, and held in her laughter with great difficulty.

Mr. Flatmate's mouth opened, uncurling his index finger as if he were about to say something, but apparently decided better of it a moment later. His gaze flicked from person to person.

Clara nudged him encouragingly with her elbow. "Well, go on. Might as well answer his question, or he'll never stop asking."

"Uh, right," said Mr. Potential Flatmate, a bit perturbed by their behavior. He edged slightly away to dodge her elbow, which poked the side of his thighs. "Neither… I'm from Leadworth - I, er, I work - used to work at the local hospital there."

"Leadworth!" he exclaimed, and then frowned as if he had just eaten something terrible. He let go of his shoulders with a great flourish, giving them both a pat. "Never heard of it until now, sounds a bore!"

"Also, um, how… how did you know I was a nurse?" he stammered, taking a few steps back once he was released.

The Doctor grinned. "Simple, really. Process of elimination. What's your name?"

"Uh… right. I mean, Rory. My name's Rory. She-" he gestured towards Clara's general direction, "-she said you were looking for a flatmate?"

"Yes. Yes, indeed I was." He shot Clara a disapproving glance from the side - it was clear she was trying to get him to make new friends, which he really did not think he needed. Not at the moment, anyway. And he didn't want her thinking she could overstep her bounds every once and a while and get away with it - she really couldn't, not without consequences. Something he thought she would have learned ages ago...

...But the fact that he had just been thrown out of his old flat and only managed to get Clara to lower her price through excessive use of the magic word ("please"), really said something about his current financial situation. And he can tell Rory was desperate, too - which was good. He could work with desperate. "I suppose you're it though, eh?"

Rory's eyes widened. "What? Really? But we've just met."

"Yeah, why not?," said the Doctor, a grin once again spreading over his face. "You've come all the way from boring dot-on-the-map Leadworth to big-bold-text London, seems as if you deserve a bit of adventure in your life! How does that sound?"

"But—" Rory shook his head, almost as if he couldn't believe what was happening. He hesitated. "I don't even know your name."

"Call me the Doctor," he said. He offered a sort of half-bow, straightening his bow tie, and spun around to pull open the door. Martha was going to text him in a few minutes about the results of the riding-crop-dead-body experiment, and he needed to get that checked out and over with by the end of the day - the entire case was riding on the validity of the man's alias, and there was still a lot of work to be done.

Before he ducked out of the room, however, he gave the nurse one last little tidbit of information, and a piece of advice he sorely needed: "The address is 221B Baker Street, meet me by seven. Ooh, or eight. Time's tricky. And Rory, remember this: don't blame yourself, you had nothing to do with it."

He waved a goodbye to the stricken-looking nurse, and walked out.

An oversized eleven-year-old dressed in a tweed jacket and bow tie. That's who he was. Out of all potential flatmates in the world, a slightly loony, personal-space invading oversized eleven-year-old, who'd somehow known that he was a nurse, new to the big city, and who-knows-what-else. Rory wondered for a moment if he had researched him prior to their meeting, but dismissed that suspicion quickly, as he was really definitely not significant enough to warrant that sort of digging. But how else could he know? And especially with his little parting statement - don't blame yourself - he had heard that so many times over the past few days that it had become a sort of mantra in his head, something even he told himself sometimes but couldn't quite bring himself to believe.

But... he didn't seem awful.

Odd, maybe.

But not completely awful.

And it had been a very lucky break for him, running into the girl who happened to be the daughter of a landlady. By some twist of fate, when he had gone out for a walk in London, pondering his own financial situation and getting quite a bit depressed at his bad luck, he had bumped into the girl - Clara - and then it had all gone a little something like this:

"Oof- sorry, sorry, sorry, you okay?"

"Blimey, watch where you're goin' next time! You could put someone's eye out with that nose of yours!"

"Sorry, I know, I - I was looking at the flats. Sorry…"

"Oh, stop apologizing, I was only kidding. Wait a moment, the flats?"

"Oh, yeah. I'm looking for a vacancy."

"Lucky you bumped into me, then! D'you mind sharing a flat with someone?"

"What? No, I suppose I wouldn't-"

"Then c'mon, I'll introduce you."

And the rest was history.

So by seven PM, Rory approached 221B Baker Street with a bag slung over his shoulder.

The first thing he noticed was the bright blue color the door was painted in, with the number inscribed in white on the side of the door, which he had nearly missed the first time going searching for the flat. The color and position of the number made it completely different from every other door, though, so it was unlikely he'd be unable to locate it again, with it standing out like a sore thumb among the other black doors with their gold lettering.

He hesitated on the steps, before bringing up his knuckles to knock on the door. Before it made contact, the sound of a cab pulling over from behind him distracted him, and he turned around. It was the Doctor - he handed the driver a few bills and got out of the car, wearing a bright smile that was in equal parts annoying and infectious.

"Hello, Rory!" he greeted with an enthusiastic wave. "You showed up!"

"Was that... really so surprising?"

"Well, no - who could resist this?" The Doctor vaguely gestured towards himself.

Rory chuckled uncertainly, turning towards the flat. "It's a really good spot. It must have been expensive..."

"Isn't it? But the great thing is that I managed to get it discounted! Ha! The landlady's daughter knows me, you see, I helped her out with something a while back."

And it was just at that moment when Clara opened the door to their flat, a plate of pastries in her hands.

"I think he knows by now we're familiar with each other, Doctor," she remarked with a playful roll of her eyes. "Welcome, by the way. I've made some cookies! Don't you dare be shy, take as many as you like."

The Doctor gladly grabbed a handful of Jammy Dodgers from her plate and headed inside. Rory followed after him almost numbly, once again feeling as if he was getting swept along by a particularly strong tide, and murmured a thank you to Clara (he took an oatmeal raisin cookie from her plate after receiving a doe-eyed look that was probably meant to be cute, but somehow came off as incredibly scary).

Once he was inside, he frowned, turning about. It was much roomier than he had expected it to be, judging by the outside - which was strange but not necessarily bad. More room was good - meant he could at least get a bit of privacy around in there. The second thing his eyes were drawn to was the sheer mess on the tables, the chairs, even the bookcases. Bits and pieces of odd metal parts lay strewn about everywhere, books and papers piled high in the chairs along with boxes full of other random knick-knacks half-open on the floor. Half of them looked vaguely like things he recognized - there was a box filled with screwdrivers in the corner for some reason, and a TV laid on its side, unmounted.

Most of it, however, looked like random unidentifiable rubbish.

He nudged a metallic, orb-like knob sticking out of the coffee table dubiously, and jumped back when it made a loud ding.

"'Sho, whaddya think?" the Doctor asked around a mouthful of pastry.

"It's," Rory hesitated, "nice. It's-"

"Bigger on the inside?" he suggested with an air of anticipation.

"-really cluttered," Rory finished, letting his bag drop onto the only bare spot on the sofa. The papers piled haphazardly atop it fluttered from the impact, some of them drifting towards the ground.

The Doctor's smile seemed to wilt slightly. "Oh," he murmured, sounding disappointed. "I suppose that's bad, isn't it?"

He stole the last of the Jammy Dodgers off Clara's plate as consolation, and she shot him a frown.

"I can help organize tomorrow morning if you'd like," she offered. "Oh, and the bedrooms are over there - there's only one of them, but I doubt that'll be a problem for you two."

"Thanks," Rory said, apologetic. "It's no problem at all."

Clara's eyebrows rose slightly in response. "...Thought so. That's totally fine, by the way. We're all-accepting around here."

"Uh, what? ...Oh." The implications of her statement slowly but surely dawned on him, accompanied by widened eyes and a rising flush. An objective finger punctured the air, sudden traumatic childhood memories from a few years back resurfacing- "No! No, I'm not- we're not sharing the bedroom-"

"I'll take the sofa!" the Doctor volunteered almost gleefully. He seemed completely oblivious.

Rory just nodded, gulping. "Great. I'll take the bed, then."

"Glad that's settled," Clara said with another innocent-yet-not smile, and whirled around with the half-empty plate of pastries clasped in both hands. "Just call if you need anything, but remember, I'm not your governess, I'm your landlady."

"Only until your mother comes back from vacation, Clara, so don't get any big ideas!" the Doctor called after her retreating form.

"Which is in a few months at the least, so you'd better get used to it. Bye!"

And the door shut behind her, carrying an air of finality. That's it, Rory thought to himself, and turned to face his new flatmate- I've officially moved in.

The bedroom down the hall was small. It basically had enough room for a bed, a desk, a chair, and a closet, and room in between to walk about a few paces. Rory sat down on the bed, letting out a breath of air slowly. The pressure of his phone against his leg reminded him of something, and he took it out from his pocket, flipping it open.

Well, no better time than now, right? He dialed Amy's number and held it up to his ear, sorely hoping he wasn't interrupting anything (last he knew of, Amy still had that kissogram job, and he'd learned not to call too late into the evening lest someone else from the many parties she attended picked up the phone instead). He was slightly relieved when someone answered, and he couldn't hear the sound of loud music in the background.

"Hey!" he greeted enthusiastically. "Hey, Amy, it's me."

"Oh, Rory! Hey!"

Her voice sounded slightly tinnier over the phone, but her Scottish brogue was comforting and reminded him of times in Leadworth, bringing a slight ache in his chest.

"No party today?"

"Nah, decided to take a break over the weekend. What about you? How's London?"

"London's great. It's, you know, London. Big. Populated. How's home?"

"Same old, same old. Got asked out by Tim yesterday, can you believe it? He thought since you left and all..."

"Really?" he chuckled nervously, fingers tightening on the phone. "You... you didn't..."

"'Course I didn't say yes, stupid!"

He fought the urge to sigh in relief, but the resulting silence was enough for Amy to figure it out anyway. She giggled into the phone, the sound clear and high.

"Come on, Rory. Don't be so clingy. Have you moved in yet?"

"Uh- yeah. Yeah, I have, actually. I've got a flatmate though, I can't really afford a flat of my own yet... He's a bit weird, but not too bad. He calls himself the Doctor - what kind of name is that?"

"The Doctor?" Amy repeated over the phone with an air of incredulity. "You mean, 'greatest detective in England' the Doctor?"

"Is that what he is? I don't know, haven't thought to look him up..." Rory rather doubted he was really what Amy thought he was. For some reason, he didn't exactly give off the impression that he was a genius detective or anything. But then again, his brain supplied him with the unnerving way the Doctor had just known information about him - and he couldn't forget the advice he had gave, either. That advice that followed him everywhere, ever since that incident...

Maybe the genius detective thing wasn't as far-fetched as he had thought, but he still shook his head. "I doubt it, he probably isn't the same bloke."

"Come on," Amy said. "How many people are there that call themselves 'the Doctor'? What does he look like? I'm a really big fan of his - he's in the news all the time - which you wouldn't know since you barely keep up with current events..."

Though her tone was teasing, it was true, and it hurt a bit. He had stopped looking at the news so often, after- Rory shook his head, taking a breath and focusing on describing what his flatmate looked like. Anything to keep from going down that trail of thought.

"Um, today he was wearing tweed and a bow tie, and his hair is all... quiff-y. Oh, and he's kind of got a chin."

"Oh my god!"

Rory jerked the phone away from his ear, wincing.

"Your flatmate's him! The Doctor! I can't believe it, he's a genius!"

"So I've heard..."

"Remember that Prisoner Zero case around a few months back? That was him!"

Rory remembered that quite clearly. An escaped convict from across the country had raised a lot of alarm, but he had managed to get in contact with his friends before the police could find him. Which meant a massive amount of identity theft had gone on, with all these disguises and whatnot, but he'd heard somebody had figured out all of the convict's aliases and put him back on death row. It was one of those things that the news reported on constantly for about a week, but was forgotten quickly.

"So he's the one who caught him?" he asked dubiously. "Are you sure?"

"Rory, which one of us watches the news? I'm sure! A guy who calls himself the Doctor, with a chin that can cut glass - it's got to be the same person."

He opened his mouth, about to say something - and yes, maybe Amy's sudden obsession with his flatmate made him feel a little... left-out - but he was interrupted by a noise on the other end. Was that someone knocking?

"Ooh, gotta go. Aunt's home. Tell me about him later!"

"Oh - uh - I'll call you later, lo-"

The line went dead.

"-love you," he finished lamely.

He stared at the phone in his hand for a moment, and let it drop on the bed with a short sigh. Phone calls with Amy usually tended to end like this - all sudden, and usually because of her kissogram job or her aunt or something - and he, of course, didn't blame her for it. She had her own life and everything. And he had his. But sometimes he wished that... one day, she'd be a part of his life, a real solid part.

Going over to London didn't help that at all, of course.

Rory turned, falling against the bed, and reached for his bag, pulling out his laptop with his chin buried in the mattress. Opening it up, he went to the search bar, and hesitated only slightly before typing in 'the doctor'.

The page took a moment to load.

834,000,000 results.

The first link was for some kind of website titled The Science of Deduction - he frowned, skimming over the short description provided, and then scrolling down the page. Further down, it became mostly recent news articles. A bank robbery from a week back, kidnappings, terrorist attacks, all London-based and all having one thing in common: somebody called the Doctor had caught the person or people responsible, like some sort of superhero.

"This is only one of numerous cases Scotland Yard has solved with the help of the Doctor," one article stated. "Many say that he is a genius..."

"'He helped me find my son Jamie,' reported 21-year-old Nancy Hoath. 'He had been missing for over four months. I nearly gave up hope, and this man came and found him for me...'"

And then Rory happened upon a picture, attached to one of the news articles, of a man with a prominent chin, bright green eyes that looked a tad wild, a red bow tie fit snugly on his neck, and brown hair swept to the side in a large quiff. It had been captured candidly - he was glancing off to the side, a half smile on his face as if he was sharing an inside joke with a person outside of the shot. It only took a moment's glance to confirm it.

His flatmate was a detective. A good one, too. Like something out of those old mystery novels he'd read when he was younger. Now, he supposed, it made sense how he'd known a lot about him at their first meeting, and he remembered the weird way he'd been looking him up and down when he had first entered the room. Had that been - what - analyzing? Had he gotten analyzed by him?

Rory nearly shivered. It was a weird feeling, knowing that somebody knew stuff about you, and having no power to stop them from knowing stuff, however personal it might be. Moving in with him... maybe that had been a bigger commitment than he'd originally thought.