I blame #setlock for this. The fic is my attempt to wrap my head around certain assumptions, my apologies.

If you are going to read this, please be aware that my story contains spoilers for season 3, episode 2.

As always this work has been betaed by the incredible SwissMiss. You are amazing!

Now, if you are still with me, go ahead and read, do not enjoy, and perhaps leave a comment, if you find the time!

Best Man

He was still one of the few people able to surprise him. Nothing new, after all this time.

"You owe me that much, you know," John Watson stated calmly. No obvious distress showing on his face. Nothing but open conviction.

"It was her idea." Not a question. A statement. He could still deduce as much. Yet it had become increasingly difficult to read this man. At least he had the decency to admit it.

"Mary mentioned it once, she thought it might be the right thing to do." The doctor raised his chin, defiance written all over his features. "That it might help."

'Manipulative, interesting.' No use in deleting her name a second time. Rather face the fact that he would have to catalogue a completely new person, and add the findings about her to his collection of John Watson files. Plus he would have to alter his John Watson index dramatically. In these new days a certain Mary Morstan was number one to John, without any doubt.

"You do realise that this is not really my area," he deadpanned, trying to gain time.

He didn't even want to think about it. This was nothing anybody should ask a Sherlock Holmes to do. There were even ties involved, and he had made it explicitly clear that he never wore ties. Of course he wouldn't bring it up a second time, but he would have expected John to be able to remember that much. If nothing else. The man seemed good at deleting, better than three years ago. Better than he himself?

Unimportant, superfluous, illogical thoughts. Nothing to dwell on. The past was gone, and all he had ever wanted was a future without the thread of Moriarty. Now, everything accomplished, goal achieved, he should not waste a single thought on possibilities that in fact never were.

The new life he had led since his return was exactly what suited him best. His name had been successfully cleared, one thing his ever so annoying brother was good for. Therefore the work, which in fact he was still married to, thrived. The Yarders were queuing up for his assistance, not only Lestrade, but even a couple of other DIs from different divisions. He could pick the most promising cases, and wouldn't have to fall back on a seven for the foreseeable future. Private clients on the internet sprang up like mushrooms. And if that should not be enough, such a number of really gruesome cold cases had piled up during his absence that he honestly wondered if the morons at the Yard had stuck to solving only minor crimes to make amends for the day he should finally return. They clearly had a debt to repay.

He was once again living in his old flat on Baker Street. Mrs Hudson was still there. A few more wrinkles, a little frailer, still fussing and scolding, but no longer insisting she wasn't his housekeeper. His anchor whenever he felt like he could do with a little domesticity. Mycroft had kept all his belongings, and now everything was in perfect order, in the way only he could organise a flat. The fridge was exclusively his at last. To be stocked with any variety of body parts, human or otherwise, he would deem fit. There was even an extra room vacant now, upstairs, which he planned to use as an extension of his kitchen laboratory, someday, not immediately, but whenever he felt he could muster enough energy to start the project. So it was all fine, indeed.

Even his best friend John seemed to be so amiable these days, perfectly at ease, smiling his flashing smile, especially when in the company of his bride-to-be.

There was no more nagging and scoffing, nobody to urge him to eat, or sleep, or drink his tea. Nobody who would raise a disapproving eyebrow if he felt like sulking over a minor inconvenience, nobody to yell at him when he felt the need to throw a tantrum. Nobody to complain when he decided that the early morning hours were exactly the right time to work on dodecaphonic music improvisations with his violin. Perfect harmony. Except for the fact that there was no audience for his drama, just the skull...

On the rare occasions he met John alone these days, the man was always polite, if a little detached. No more calling one another an idiot. Those days were gone. This was a good thing, wasn't it? Calling your friend an annoying dick or a bloody machine was not socially acceptable. So he had been told. That episode of his life was over and it should feel good, shouldn't it?

He had just been asked by his one and only friend to be the best man at his wedding, and he should proudly accept it. That's what friends do. 'Friends protect people': first they jump from rooftops, and then they are best men at each other's weddings. Duties. He had to learn social standards, niceties, if he didn't want to be alone again.

'Alone protects me', still his firm conviction. Alone doesn't hurt half as much as feeling lonely. After three years John had moved on with his life. That's what the living were supposed to do after a moderate period of grieving. Normally that would even be appreciated by the deceased. Yet in most cases death was irreversible.

He really should feel grateful for the good doctor. John had moved on. The loss of his friend had even made him better, stronger, wiser. A man you can depend on. A man who struggles but faces his destiny. The perfect match. A man to marry and raise a family with. A perfectly logical conclusion. He really should not be surprised that it was someone as smart as Mary who had come to the same result. Add the fact that she was of a suitable size, age and gender, and rather pretty going by common standards, he should not be surprised that John was an all but married man, when Sherlock finally managed to return.

It hurt more than the head-butt.

Sentiment: stupid, stupid, nothing more than a chemical defect. If anything he could deal with chemistry. There were chemical ways out of this limbo. Alone protects, chemistry helps.

He could do that. He had always been a great actor. Camouflage was part of his job as a detective. What was a day at a wedding for a brilliant mind like his? Numerous new people to deduce, plenty of exquisite food, a toast to the groom, composed of a variety of intricate adventures they had experienced in their time together. A little dance, perhaps with Molly; no, Mrs Hudson preferably. The day would be no longer than any other. Time can be measured objectively. He could do that, in fact he would. He had to, John had left no doubt about that. It was important for Mary to show the world that they were still friends, that she played a vital role in their friendship these days, that she was accepted by him. No more rumours. He would be the best man at his friend's wedding. Mates do that sort of thing for one another. It was all fine. And at the end of the day he could return to his own life of solving crimes and indulging in chemistry.

Still, he could not help his face betraying his disgust at the prospect of dealing with such tedium. At least that was what he wanted John to read in his expression: merely annoyance about a minor inconvenience, nothing else, no feelings...

"Listen, Sherlock, I didn't want to bring all this up again, but can you even imagine what I went through? Your betrayal... I mourned you."

John was clearly uncomfortable with his next words.

"When I visited your grave the first time, I told you that you were the best man I ever knew. I've ... Well, that's not my point right now, but for the sake of our friendship, for the sake of my marriage, I need you to be the best man one more time. After all you have done, you owe me that much."

Such an effort, so many big words. This woman clearly meant a lot to John.

"Stop explaining any further, John, your motivation is obvious enough. I can see that you want to avoid a future that is overshadowed by the past. People would keep talking and even though there was a time when you could have tolerated any misinterpretation of our relationship, you now feel deeply obliged to your wife in spe to erase all doubts for the future. I can see all of this without your painful attempts at explanation, and will of course fulfil my obligations."

With this, he switched off the microscope he had been working at, rose, and headed for the door. Blank face, empty eyes, yet he still managed to draw up the corners of his mouth and wink for his best friend.

"Must dash, there's a chemical experiment waiting for me at Baker Street. Why don't you drop in on Molly? That was obviously your initial reason for coming to Bart's, to give her the invitation. She'll be delighted ."

There, it was all over. Quite easy in fact. That had been a sensible conversation between friends. He could still manage that.