Hello everyone! This is a translation of the fanfic I have working on (hum-hum procrastinating on) for two and a half years: my version of the story of Sebastian Moran and Jim Moriarty. I am very happy to finally publish this fanfic. It's a series of OS following each other: each chapter is an stand-alone story, an episode in Jim and Sebastian's life, but the whole thing follows the evolution of their relationship. There will be feels, fluff, humour (I'm trying), character development, plot twists, and feels. A lot of feels.

I'd like to thank my two French beta-readers, Anso and Louise, for their feedback on my story, their corrections, and the verbal slaps that I quite frankly deserved. Special thanks to Anso for her amazing drawings (I am still crying). And thank you to my friend Arsène, who helped me figure out some complicated plot points, gave me some really good ideas, and supported me all throughout this project.

Thank you also to my English-speaking beta Finrod for proof-reading everything. I'm using DeepL to translate the text and I'm correcting most of the mistakes by hand, and she makes sure I don't forget things or use typical French phrases.

Warnings: this fic is about two criminals, who both have a pretty dark backstory. The warnings are mostly the same as those in the Sherlock series, but I'll still mention them in each chapter, and try not to give too many spoilers. If you have a specific trigger that I haven't written, don't hesitate to send me a DM and I'll tell you whether it's in the fic.

Recurring warnings (in most or every chapter): physical violence, death threats, white arms and firearms, murders and diverse other crimes.

Chapter 1 – Bumpkin

The streets of London never seem to change. Every day the same routine, the cars that honk, the passers-by that hurry, head down, all under a lead sky constantly pouring out a thin drizzle. Boring. But Sebastian had nothing more interesting to do than stare out the window of his flat at the street below, deploring the misfortune that life seems to make rain on him, as if he were himself but a vulgar London street.

First, the war. Sebastian had enrolled in the army to serve his nation, but also for the thrill of adventure and danger that it brought to his life. He had soon realised that taking someone's life didn't bother him the slightest, if it could ensure that himself, and the people he cared for, stayed alive. Everything had ceased a bit over a year ago, when he was wounded at the arm. That wouldn't have been such a problem had he been a simple foot soldier, but he was a sniper, and without total control over his limbs he could make fatal mistakes. Thus he was repatriated to London as his wound healed; but he had no delusions about his chances of going back to the fighting line: the army would favour younger recruits.

He had had to live on war pension and a few lousy jobs before he was offered a real employment, up to his personal skills. He took advantage of the comfortable salary that came with it to piece his life back together, finding himself a nice flat, a few habits he could go back to when he wasn't working, in short something that really belonged to him. Sebastian liked his solitude and his dependence to no one – except of course his employer, who gave him his salary each month, plus a bonus for each successful operation. He liked his work, which changed all the time and didn't risk to fall into a boring routine, and the thrill of danger it brought him and that he had missed since his return from Afghanistan.

Until once again, misfortune befell him. His employer and his lodger seemed to have coordinated to lower his wage and increase the rent all at once. Sebastian had never rolled in gold, and today less than ever. Since moving out was out of question, he had but one solution: find a flatmate.

And there he was, leaning on the window frame of his apartment, staring at the street as he waited for the complete stranger who, according to flat sharing websites, would soon become his best friend. Sebastian highly doubted that. He couldn't say he had never had friends; whether it was childhood friends or army comrades, he had tied strong links to others; but having lived in an environment where anyone could die at any moment, he had learned to not grow too attached to others. And he couldn't see how a London bumpkin with no money could win his sympathy, him… another London bumpkin with no money, as well. Sebastian sighed. Sometimes, he really made himself tired. His current condition wasn't exactly brilliant, but he knew he was still above the British common folk. It wasn't vanity, it was only, from his perspective at least, fact. He was a veteran of the Afghanistan war, he had a job that most people only imagined through the illusions that Hollywood poured onto them, he wasn't a nobody. And yet, to the eyes of everyone, he had to maintain that image of mister-nobody, if he didn't want to lose his job, or worse, his life.

…Did we forget to mention? Sebastian Moran was a sniper employed by the most dangerous criminal in London, a man that he had himself never met, but whose shadow hovered over his network like that of a gigantic spider ready to annihilate the littlest fly stepping foot in his web.

Among all the passers-by hurrying along the sidewalk, a young man stopped on the doorstep of the house. He was dragging a luggage, and carrying a big cardboard box under his free arm. Before Sebastian's eyes, he set the box down on the wet pavement and took out of his pocket a piece of paper that he quickly consulted, before checking the number on the door. By this point, Sebastian should already be making his way towards the door to welcome his "future new best friend" (my ass), but instead he just let out an exhausted sigh. The young man rang the doorbell; the shrill sound it made resounded throughout the apartment. Sebastian didn't move an inch, letting the lodger open the door.

"Not my problem…" he eventually muttered while lighting a cigarette.
If he had to live in the company of someone else, this was probably the last one he could smoke in his house. Sebastian didn't give a damn about his lungs' health: with his job, he was almost certain the he'd get himself killed before cancer could show up.

He could vaguely make out the sound of the newcomer talking with the lodger down on the first floor, and he made his way slowly to the door, before leaning down against the wall. He had barely tidied up the apartment: compared to the day before, it was clean, from an outside viewpoint, it was an awful mess.

Three knocks came from the apartment door. Sebastian stood up and ran a hand through his short hair – more a habit than a real necessity – and opened the door.

The man standing on the bearing looked slightly out of breath: despite the help offered by the lodger, he seemed to have insisted to bring up the luggage and the cardboard box upstairs by himself. His black hair was slicked back but a bit untidy, and he had tired little eyes that gave the strange impression that he was looking right through you. He was small, compared to the veteran, and his slightly too-large clothes added to this impression of fragility.
"Bumpkin" Sebastian thought to himself.

The bumpkin held out his hand.

"Hi, I'm James, your new flatmate," he said in a confident voice. "You must be Sebastian?
-My flatmate's name is Richard Brook," said Sebastian while staring suspiciously at the outstretched hand.

"Richard James Brook, but people call me James," the young man explained.

Who on Earth went by their middle name? Sebastian resigned to shaking James' hand. It was cold, almost like a corpse. Now that he thought of it, that's also the feeling his eyes gave – dead, expressionless eyes, while the rest of his face was smiling.

"Come on in," said Sebastian as he made way for James.

The latter entered the apartment, dragging his luggage behind him, and left the box on the bearing for now. In an instant he looked around the living room, his gaze seemingly noticing every last detail. He abandoned his luggage to tour around the flat, which didn't take him much time, under Sebastian's vigilant watch. He walked around as if he already knew the place like the back of his hand, with an air of owner.

"There are two rooms," he remarked. "You normally live alone, right?

-I'm not the architect. Do you mind that there's two?"

James turned towards him.

"No, it's just that I expected to sleep on the sofa."

He went back out on the bearing to get his cardboard box, which he then dragged alongside his luggage to the empty bedroom. The whole flat reflected Sebastian's tastes and habits: posters and bills pinned to the walls, a vest spread across the arm-rest of the sofa, a coffee mug on the pool table, random trinkets abandoned on shelves, a newspaper left on the ground… only the second bedroom had be thoroughly emptied and cleaned for the arrival of the new resident. Sebastian went back to the window to finish his cigarette (the newcomer hadn't made any remarks about the smoking, but he had clearly noticed his look of disapproval when he saw the stub), while James unpacked his things. The sky outside was still as grey, and the unceasing merry-go-round of the people in the street was still as boring, but he'd rather let his mind wander than have to take part in social interactions.

"We haven't had the occasion to properly introduce ourselves on the website," said James from the next room. "Where do you work?"

Sebastian groaned. So much for solitude. Thankfully his employer had provided him with enough documents and information to sound credible when he claimed to have a 'normal' job.

"I work in security," he answered. "You see the big buff guys standing in the entrance of stores? That's me. Well, it depends… sometimes I get hired as a bodyguard."

A whistle came from next door.

"Wow! Bodyguard? That can't be easy every day!

-And you?

-Me? I work at Saint Bart Hospital, in the IT department.

-Why'd you need a flatmate? Usually, IT pays well…?"

James let out a bitter laugh.

"You think! I'm just an assistant, I barely earn more than the minimum wage. At least I have my theatre group to make ends meet."

Sebastian eventually left the window and started putting a little more order in the living room. At first glance, James seemed to be a completely lambda guy – a small day job, a hobby, some financial difficulties… the young man's life was similar to the mask that the sniper was wearing, but they were really opposed. A computer scientist with a passion for acting, and a paid assassin working for the most dangerous man in the city? It would be difficult to build a sincere friendship while maintaining the illusion of a normal life. The "bumpkin" looked like a nice guy, with whom he could get along – without necessarily becoming the best of friends. It was hard to find common points with a man of the common folk when your own life was strewn with corpses, but Sebastian caught himself thinking that he could at least make the effort to try.

oOoOoOo

The streets of London never seem to change. Every day the same routine, the cars that honk, the passers-by that hurry, head down, all under a lead sky constantly pouring out a thin drizzle. Boring. But James Moriarty was above all that; both literally (he was on the highest floor of a building and was watching the street from dozens of meters high) and metaphorically. But in order to conduct his plans, he would need to blend into the masses of the mortals.

He abandoned the window to walk towards the computer set on his desk. Blending into the masses rendered him mortal and vulnerable as well, which did not please him at all. He would therefore have to find a trustable person to associate himself with… without putting himself in danger by revealing his true identity. Anyone would have been depressed by the problem; James, on the other hand, was enthusiastic at the idea of hiding behind a mask and driving other people nuts. He liked having all the cards in hand while others thought they controlled the situation. How presumptuous they all were. The complete plan to create a false identity was long. Most people thought they'd only need to falsify a few papers; but Moriarty never did things halfway: if he had to create a persona, he would give him a situation, hobbies, friends – he shivered at the thought – anecdotes to tell…

He had gotten a job, which he would have yield to for a while before he could make his persona evolve unsuspiciously; but more than a job, he needed to invent a social situation for himself. Living alone was a bad idea, he would be vulnerable, whereas a flatmate could easily serve as an excuse in many situations. He had therefore chosen a member of his staff: Sebastian Moran, a sniper and ex-soldier in Afghanistan, seemed to be a good choice. The man lived alone, but it had been easy to force him: he had lowered his salary, and forced (in a not-so-legal way) his lodger to increase the rent. The results came quickly: less than a week later, Moran had put out an ad on a flat sharing platform. James now only had to put in place the last puzzle pieces of his mask. Sitting down in front of his computer, he started writing a short response to the ad that he had been waiting for for a week.

Richard James Brook, 29 years old, computer scientist – looking for flat mate near St Bartholomew Hospital

He added a few information about himself (or rather, about Brook) before sending the message to Moran. He now only had to await his answer – he had taken the precaution of hacking the website so that Sebastian wouldn't receive any other offer – and the illusion of Richard Brook, 29 years old, computer scientist, would be complete and ready to use.