Disclaimer: I do not own Sherlock; this is just fanfiction.

A/N: This was meant to be much shorter. Sherlock just wouldn't shut up. It also hasn't been brit-picked, so my apologies for any Americanisms. There is also blatant use of dialogue from A Study in Pink. I figured it was appropriate. Also, if you've been reading Bodyguard, um, yeah, don't hate me. Heh.

Summary: inspired by this prompt: "Sherlock learns that a spat of recent killings was done by a professional assassin. A man so feared that the criminal underworld is afraid to whisper his name. Sherlock goes off on his own to track him down, and is captured.

Sherlock braces himself for a cold-blooded killer, with nerves of steel and no remorse, with a reputation for ruthlessness that makes several hardened criminals check their closets before they go to bed - and meets John. Easygoing, good-natured, cuddly jumper-wearing John. Who thinks he's brilliant and hilarious, and can he take him out for a coffee?

Cue the weirdest courtship ever. Like, dates being crashed by Russian assassins, epic gunfights in the middle of London, Lestrade and the Yard going WTF, Mycroft questioning his brother's taste in men, etc."

Sherlock and John's relationship wasn't what one would call "average". You see, they met after Sherlock stalked John for a week without eating and John in turn shot Sherlock with a tranquilizer gun, kidnapped him, and then forced him to drink tea.

It's complicated.

It started with the investigation of a strange rash of killings of the most random people ever -a Mafia boss, a politician, a CEO's wife, a lion's mane jellyfish, a chemist- all killed with bullets from the same gun. Unfortunately, the gun was unregistered and the shooter was nowhere to be found, which led Lestrade to bring in Sherlock.

"You're looking for an ex-soldier, probably returned from service three years ago, who only recently broke his contract with the Mafia. Five feet, six or seven inches, British, mid-30's," said Sherlock, kneeling over a dead man's body. He couldn't help but admire the perfectly clean bullet hole that went straight through the man's heart.

Lestrade shook his head. "The Mafia, really? How could you possibly know that?"

Sherlock gave Lestrade a look. "One gun kills six people the Mafia has grudges against; Mafia boss gets shot by same gun; suddenly the shooter starts killing people the Mafia doesn't even care about? Of course the shooter broke his contract. He killed his boss. Need I continue?"

"Never mind," sighed Lestrade, scrubbing a hand down his face.

"Text me if you find anything else -which you won't, obviously." And with that, Sherlock sprung up and began striding away.

"Wait! Who's this then?" Lestrade yelled exasperatedly, gesturing to the body.

Sherlock twirled around and drawled, "A terrorist. Who else?" And before Lestrade could get another word in, Sherlock was gone.

After sifting through the fifteen people who complied with the data and narrowing it down to two, one John Watson and one Sebastian Moran, it was all too easy to figure out who the shooter was; Moran was simply too tall. The true difficulty was in catching the shooter. Watson had multiple foxholes, knew when he was being tailed, knew how to blend into a crowd, and most importantly, knew how to hide the evidence. It was a wonder Lestrade had managed to get as far as he did. Watson was tricky.

And Sherlock loved it.

Sherlock loved it so much that while he was busy twirling around one of Watson's latest hits in the back of a dark alley, he barely had a chance to observe the flash of the rifle barrel from the window of the building opposite the alley before the tranquilizer dart hit him in the neck.

Several hours later, John, with his beloved Sig nestled against his hip comfortingly, bustled about his favorite London flat as he waited for the hot water to boil, carefully locking up his second favorite sniper rifle before double-checking the ties around Mr. Holmes's hands and feet. He frowned as he looked at the pale, skinny man tied to the chair. "You really need to eat," John told him. "You're practically skin and bones."

Holmes didn't respond, and while John admired how talented the P.I. was at faking sleep, he knew that by now the sedative had worn off, and the P.I. was surely awake.

The tea pot began whistling, calling John back into the kitchen. When he walked back into the living room, the P.I. looked just the same as he had when John left. "Oh, come on," John said. "I know you're awake. Even if you weren't awake before, the kettle definitely woke you up."

Holmes's eyes snapped open, and John blinked in surprise at the intensity he saw in the other man's gaze. He couldn't quite decide what color his eyes were, though. They were gray, blue, and green all at the same time. It was fascinating.

John was a sap. It was his deepest, darkest secret.

"I made tea," he said.

Holmes raised an eyebrow.

"It's not poisoned, I promise," John told the eyebrow. "See?" He poured some of the tea from the left cup into the right cup and then poured some of the tea from the right cup into the left cup and took a sip. He set the other cup on the coffee table. "I just want to talk to you, so I don't really see any need to keep your hands tied." He looked at Holmes warningly. "Don't try anything." The only response John received as he bent to untie Holmes's hands was a slight squint and a curious tilt of the head from the man.

In a sudden rush of movement, John stopped the man's hands before they could incapacitate him, one fist an inch away from punching him in the stomach and the other hand with its long fingers a hair's breadth from curling around his neck. John flicked his eyes to the ceiling in exasperation. "I told you I just wanted to talk."

Holmes pulled back of his own accord. (Was that a smile tugging at his lips?) "Is the tea still an option?"

John grinned. "If you behave." He handed the cup to Holmes, who brought the cup to his lips, sniffed, then took a small sip.

John licked his lips. "Impressive bit with the attack just now. Didn't see that coming," John told him.

"Of course you didn't."

John quirked an eyebrow. "So, I suppose-"

"Of course you do," muttered Holmes.

John ignored him, continuing, "You'd like to know what I want to talk about. I-"

"I already know."

"Oh?"

"You want to know how I did it. How I figured out it was you and how I've managed to follow you for so long."

John blinked several times. "Yes," he said, curious. "That's exactly what I want to know. You're not the average P.I., are you?"

"Consulting detective," Holmes said flatly.

"What?"

"I'm a consulting detective. Only one in the world. Not a 'private investigator'," he spat.

"Ah," responded John, bemused. "My mistake. So what is it you do, exactly?"

"Read my website, Science of Deduction, and you'll find out." He said, offering John a fake smile.

John refrained from rolling his eyes. "Well, then answer my other question. How did you do it? How did you know it was me?"

"I observed. A string of Mafia related deaths from August 2010 all shot with the same caliber bullets from the same gun at the same angle -obviously the Mafia's pet assassin. But the first murders were messy, as if the shooter was used to a different gun, a British Army L9A1 or a Sig Sauer P226R, to be exact, so the shooter must be a British army vet, highly skilled, too, probably even a crack-shot. But then the Mafia boss himself and several other high-ranking members are shot with those same bullets in January 2012; suddenly those bullets start ending up in an assortment of victims, none related to the Mafia at all, so we know the shooter's broken his contract and gone solo, killing those Mafia members' to ensure his safety." Holmes said this all in his deep voice so quickly that John had no idea how he managed to breathe.

"How did you know it was a 'him'?" interrupted John.

"Shot in the dark. Good one, though. Statistics say the shooter would be a man, and it's even less likely the Mafia would hire a woman, no matter how good she is."

"So what else was there? Surely that wasn't enough to go on?"

Holmes's lips twitched upward. "No, that wasn't it. Taking into the account the angle of the shots, we can conclude that the man is five feet, six or seven inches. We know he has unique but strong morals despite his occupation because of the one failed hit, Victor Trials, when the assassin had the chance to finish the job but chose not to because there was a child in the way. Taking into account his strong morals and the fact that he killed his own boss, we can conclude that he worked for the Mafia because of monetary issues, not because of any personal leanings. Monetary issues means he wasn't in the army long enough to rank high enough to receive a good pension: mid-30's in age. The assassin also has plenty of bolt-holes and knows every street and alley in London, so unless he's a genius like myself -highly unlikely- he's lived in London before he went into service. Being an assassin means he most likely lives alone. So, who previously lived in London then returned from service in 2010 with a relatively low rank, captain or lower, with a reputation for being a crack shot, lives alone, and is five feet, six or seven inches tall? You. Even more likely, since after researching I found out that you were an army doctor -that explains the precision of the shots; you knew exactly where to aim."

John stared at the consulting detective in disbelief. "That. Was amazing."

"You think so?" Holmes looked confused.

"Yes, yes. Quite... extraordinary." (That was a smile tugging on Holmes's lips, John was sure.)

"That's not what people normally say."

"What do they normally say?"

"Piss off."

John grinned.

"I'm surprised you didn't shoot me," said Holmes. Now it was his turn to look bemused.

John shrugged. "Not really my thing."

Holmes furrowed his eyebrows, the look on his face saying, 'Really? Yeah, right.'

"I kill those I'm hired to kill, and I get to pick and choose my contracts. Rest assured that in the future, if anyone tries to hire me to kill you, I'll say no. I might even send you a warning," John said playfully.

"Stupid," Holmes deadpanned.

John snorted. "Yeah, well, like I said. Amazing."

Holmes looked away, grinning slightly. John decided he liked that grin.

"Any more of that tea left?" asked Holmes.

John looked down at the detective's cup, surprised to see it was empty.

"Of course," he took the man's cup and went to go fill it. As he was filling the teacup, he decided that he really liked Sherlock Holmes. He'd never met anyone quite like him.

So really he shouldn't have been very surprised when he felt the cold metal of his own Sig press into the back of his neck. "I can't believe you pick-pocketed my gun. Impressive. And you escaped the chair."

"Please, Watson," drawled Holmes from behind him. "Leaving my hands untied was basically begging me to escape."

John smirked as Holmes reached around him for the cup of tea. "True," he agreed.

"Did I get anything wrong?"

"Hm?"

"About you. Was I right?"

John hummed nonchalantly. "You read the records. I went to university in London, became an army doctor, a captain. Joined the Mafia in August 2010 and... left in January 2012. Now I'm a private assassin, and yes, I do have my own, unique set of morals."

"Spot on, then. I didn't expect to be right about everything."

"I joined the Mafia because of my sister, not because of my personal monetary troubles," John said, sounding completely unconcerned about the pistol still pressing firmly against his spine.

"Your sister?"

"Yes... She owed money." John said curtly.

"Ah. Your sister! I should've known from the records!"

"Look, Holmes, could we have this conversation another time? Maybe when you're not holding a gun to my neck?" The pistol was starting to become a little disconcerting. John was worried that Holmes would start ranting again and become so preoccupied that he wouldn't even notice when he accidentally put a bullet through John's spinal cord and esophagus.

"Oh, right," said Holmes, still not moving the gun. "Dinner? There's a nice little Chinese place I've been meaning to try."

John chuckled. "I'd love to," he said. Sherlock lowered the gun and stepped back, allowing John to turn around and accept the proffered pistol. "And you can call me John," said John as he tucked the pistol into his side holster.

"Good thing we're walking out together, or else you'd have to meet my brother," said Sherlock as he strode towards the door, only wobbling slightly from the tranquilizer's long-lasting effects. John was, once again, impressed.

He was also confused. "Your brother?"

Sherlock only grinned.

Pretty please review before you favorite the story or me or put me on alert or any of that good stuff. Also, this is most likely a one shot. Although, this is a really fun universe to play with, sooooo... Idk.