"The residue Bill found in the kitchen will take longer to process. It will be easier to start with it – "

"You found the dirt under his fingernails first" John insisted, and Sherlock was reminded of his friend's insistence that they clean the kitchen table before eating at it after his experiments, and his ill-fated attempts to label the shelves because he wanted to organize their flat, at least shortly after he'd moved in. He hadn't tried to in a long time.

"And that's a reason to start with the dirt?"

"We have to have some form of order, Sherlock – "

"Why?"

The question escaped him, the question he had often wondered about, but never asked the doctor – why did he have to obey social conventions, why couldn't he leave the body parts on any shelve in the fridge, why did he have to thank people who had behaved idiotic through the whole investigation.

John blinked and stared at him.

"That – "

At the same time, they realized there was no answer, and when once upon a time Sherlock would have been annoyed at the fact, now he merely chuckled.

After a moment, John joined him. Sherlock shook his head and agreed to process the dirt first.

He assumed John was talking to Bill and Mike, maybe trying to understand the rules of this universe. A hopeless endeavour – no one had yet managed to comprehend their own, so it was not be expected that they would succeed in getting to know this one. Still, the doctor was confused and looking for answers, and if hearing about Bill's and Mike's lives made him more relaxed, Sherlock had nothing against it.

Sherlock admitted to himself that he preferred processing evidence with John to watching the brothers, and not only because this was an utterly fascinating case, but because he didn't want to see them. That he and Mycroft weren't at the best of terms was a fact that had been cemented by decades of mistrust and wrong words at the wrong time, by two different temperaments that would never be able to understand one another completely, by an exchange of information between the two most dangerous men he'd ever met. Since he'd returned, it had got better, but they never would have what these brothers had. Not simply because they were ordinary. But because Mike and Bill were different people than Sherlock and Mycroft, and despite there being a few similarities, enough to realize why this universe had chosen to give them their faces, it wasn't certain that Sherlock would have recognized them for what they were if they had looked different.

"Me and Harry "don't get on" either, as Bill put it once" John interrupted his thoughts, and Sherlock realized that it must have been easy to deduce what he'd been contemplating.

"What does she do?" he asked.

"She's a professor. Currently she's working in the United States, doing some research concerning diseases of the central nervous system. We don't speak often" John replied courtly and focused on the dirt.

It didn't take long for Mrs. Hudson to make the tea, and soon he heard John call out for him; without bothering to explain, knowing that it would annoy both of them, he left the kitchen and followed the doctor into the room that was his in their universe.

John pressed his ear to the door while Sherlock sat down on the bed and let his gaze sweep over the room. It was meticulously clean – like he'd expected from the consulting detective – and he could see a corner of a picture sticking out over the edge of the cupboard. He guessed it was a picture of John and Harry as children; he kept his of himself and his brother in the drawer of his nightstand. The wall looked strangely empty without the periodic table, he decided.

"Sit down, John" he whispered. The doctor might be curious, but he would hardly hear anything worthwhile.

His best friend sat down next to him and looked around the room as well.

Sherlock hadn't been to John's room often – mostly when he'd had a revelation or a client had shown up early in the morning – but he knew it was just as organized as this one was.

Not for the first time, he wondered what this meant to his friend. John had been on edge since they had met their counterparts. It was possible that he was uncomfortable with watching himself being what Sherlock had been when they had met, but the consulting detective didn't think so.

"It feels strange" his friend began, looking at the door, and illogically, Sherlock's stomach clenched, "to hide from Mrs. Hudson. In our universe, she'd never forgive us."

"She has "her boys" in this universe" Sherlock reminded him, making sure to sound like he minded how she referred to them usually, because he knew John would be able to tell he was lying and it would make his flatmate smile. He was right when he simply grinned at Sherlock and continued to listen to the sounds that came through the closed door.

She must have found out about the t-shirt, because she was berating John for it. Bill didn't say anything, which meant he was enjoying the show, like John would.

Sherlock shot him a glare to make him understand that a comment wouldn't be appreciated. John suppressed a smile.

He had always known Sherlock was human, utterly human, more so than many others he had met, and had of course noticed that he was showing more emotions, was opening himself up more since he'd arrived, even though he still hadn't told him much about the time he'd been away. But the difference between him and John Watson really made him see how much Sherlock had changed.

It wasn't that John was a psychopath – far from it, he was sure; after all, he was friends with Bill, and he tolerated Mike despite the obvious dislike they harboured for one another – but he was very like what Sherlock had been before –

He remembered Jim and a shudder ran down his spine. He looked down on the floor to avoid Sherlock's eyes.

He was glad their visit to the lab had been short. Just because he knew this wasn't the Moriarty they had met –

How different everything would have been if Moriarty had indeed been Jim from IT. Sherlock would never have left, John wouldn't have spent years grieving for a man who was alive. And yet –

The consulting detective was trying to conceal that he was worried, the doctor knew. Ever since they had entered this universe, he had almost constantly kept John in his line of sight – the exception being when he and Bill had got coffee and Sherlock hadn't been able to raise an objection – and he was starting to wonder if his friend thought he couldn't handle this universe. It was complicated, and at times difficult, to see the people they met as someone else and not their friends and enemies. Sherlock would be aware of that.

The weirdest part was certainly seeing himself running around – not because he didn't like this version of himself per se (how could he dislike him, when he reminded him so much of his best friend) but because it was like looking in a mirror whose image moved.

Had he given Sherlock reason to suspect that he was uncomfortable for other reasons than that they didn't know how to return home and that they had no idea how this universe worked? Was he adverse to John's attempts to make sense of all of this by watching the inhabitants of this London closely and talking to Bill and Mike when he had the chance?

Because there had to be a certain reason for John Watson being a consulting detective and Bill Holmes being his best friend in this dimension; there had to be a reason for Jim Moriarty working at St. Bart's. Because there had been a reason John had been introduced to Sherlock. There had to be. They were meant to be best friends, in any universe apparently, so why was John a consulting detective here?

"John" Sherlock interrupted his thoughts quietly.

The doctor looked at him and was taken aback by the intensity of his gaze. Sherlock had only once looked at him like this, and even then, he had barely seen it; he'd stumbled into the kitchen for his first coffee of the morning, and Sherlock had stared at him, just like he did now, and he had only seen it for a second and then forgotten all about it until months later, when he'd gone through the events of these days again and again because it had been three days before Sherlock killed himself.

"Yes?" he managed to ask.

The consulting detective bit his lip, unsure of what to say, and it was such a strange occurrence that for a moment, John was afraid he would lose him again.

"It's enough that it happened" he stated, and anyone else would have needed time to understand that he was talking about their first meeting, and that there didn't have to be any reason behind it, but John knew, and it was indeed enough.

Sherlock tilted his head to the side and listened.

"John is in the kitchen" he explained, "most likely working on the evidence. Mrs. Hudson is talking to Bill and Mike. I don't think it will take much longer".

John nodded. It was all he could do. Sherlock had once again managed to quell his doubts with a simple sentence, and he was content to wait.

Mrs. Hudson didn't stay long, proving Sherlock right, and soon Mike was opening the door.

"She's gone" he informed them, and John knew Sherlock wanted to say "obviously" but refrained from doing so, "and he's found something".

Sherlock immediately swept past him and into the kitchen, and he stepped aside to let John pass, mumbling, "I don't know who you deal with them".

John simply smiled and followed the consulting detective.

"South of the Thames... just like you said" John explained, gesticulating towards the small pack of dirt that lay on the table.

"I also started processing the residue found in the kitchen, but it is going to take a while".

Sherlock nodded and looked at John's notes about the evidence he had found under the victim's fingernails. It wasn't much. Like the other man had said, the dirt consisted of particles more commonly found South of the Thames, but that didn't mean it had to come from there. Every man in London carried dirt with him. Maybe Pike had brought it into his flat himself. It was all they had, though. And they needed to catch Trevelyan if they wanted to return home. It was entirely possible that the scientists had already moved on to another universe, but even if this was the case, they had to make sure. They couldn't let a dangerous man run around multiple dimensions.

"So do you think Trevelyan's hiding there?" Bill asked.

"It's possible" John replied, staring at the notes in Sherlock's hands, their shoulders brushing, "but we can't be sure" he continued, voicing Sherlock's objections. "There are many reasons for the dirt to have found its way into Pike's apartment, and even if it is from South of the Thames, we have nothing else to go on."

"Not yet" Sherlock reminded him.

Mike, who hadn't said a word since he'd told them they could leave the bedroom, began, "We could – "

He never finished his sentence because at this moment, someone frantically started to ring the bell. They heard Mrs. Hudson open the door and a voice they all recognized cry out "Sorry!" as the man who had just arrived ran past her and up the stairs.

Bill quickly ran to open the door to their flat, and Jim almost fell through it, panting.

"I think I know what Trevelyan's plan is".

John could only surmise from the IT tech's expression that it wasn't good.