Sherlock had them out of the hotel, with their overnight bags and passports – which thankfully they wouldn't need – and to the train station almost as soon as Mycroft was speaking alone to De Luca, arranging matters for the exchange of hostages. When he got right down to it, that was precisely what it was.

And he had no intention of being involved. Nor of having John involved, even only peripherally.

It had been less than twenty-four hours, but he'd accomplished what he'd come to Edinburgh to do, and he had no desire to extend his stay. He knew John was exhausted, and he himself was feeling the effects of too much adrenaline suddenly no longer needed, and lack of sleep, since he hadn't slept much the night before, for entirely different reasons. Certainly more enjoyable ones.

And he had no interest in this apparent nephew of his. Let Mycroft deal with the reality that his son knew who he was – he had chosen this route, and Sherlock had not. He hadn't seen it necessary to inform his brother that he had a nephew, or inform his son as to his identity, so Sherlock felt no connection, nor guilt about it.

He simply wanted to go home.

He purchased first class tickets for himself and John on the next overnight train to London and installed them in a pair of seats away from the other passengers. Thankfully, their cabin was sparsely populated, only single businessmen or businesswomen travelling overnight, all of them quiet, most of them more interested in sleeping so as to be alert in the morning when their train pulled into London and they headed off for myriad meetings, lunches, negotiations, talks. They ignored him and John, and Sherlock happily ignored them in turn. One or two of them were working, but considerately not using their overhead seat lights, so the train car was faintly illuminated here and there by the faint blue glow of laptop screens or iPhones.

John fell asleep on Sherlock's shoulder shortly after they left Edinburgh. It was uncomfortable, and Sherlock could feel his arm falling asleep, the numb feeling spreading from his shoulder down to the tips of his fingers, but he didn't shift or try to adjust John's position.

Given how he'd slipped up in the vaults, without even considering what John might think of his examination of his shoulder wound and the questions, Sherlock was quite grateful that John was sleeping against him.

He disliked making that kind of mistake, not least because he really ought to know better by now. He'd been married to John for two and a half years, and they'd been together for a year longer than that. Slipping up in that way meant he wasn't thinking, that he could make errors.

That he was human.

Blast, if John caught onto that, he might snicker.

He wondered if John would be all right, if there would be some repercussions to this he could not foresee, even him, the world's only consulting detective. He ran through various scenarios in his admittedly fatigued mind, but the problem with – or benefit to – John was that he kept Sherlock guessing at times when Sherlock thought he had him pegged.

It was both endearing and maddening, but much more so the former than the latter.

How dull life would be, without John. How much duller without Mycroft, but Sherlock thought he might be able to handle, even relish, that kind of boredom.

He kept his eyes on the window, not quite able to see the darkened scenery speeding by outside their carriage, and tried not to think at all. This was a difficult prospect. But with each minute that increased the distance between himself and Mycroft, he felt himself unwinding, if only a little. He doubted his brother even cared that he and John had gone – he had much more important things to worry about, like getting an international drugs dealer out of prison in exchange for his ten-year-old son.

Let him deal with those complications. It would likely keep him out of Sherlock's life a lot longer.

At one point, John woke up, stirring slightly. Sherlock glanced over, meeting John's eyes, which were much darker in the very dim lighting of the car. John stayed leaning against him for a moment, then stood up and stretched, and went off to find the loo. Sherlock had just gotten his arm to wake up again, all pins and needles and stabbing, itching sensation, before John came back and settled against him one more. Sherlock bit his lip – he knew he had not a leg to stand on when it came to physical discomfort that night.

"I didn't think he'd do it," John said, very quietly, after a few minutes.

"Nor did I," Sherlock admitted, still gazing out the dark window, trying to at least spot the differentiation between land and sky, but he could not.

"It would have been practical not to," John said.

"Indeed," Sherlock agreed. Practical, yes. Acceptable? Perhaps not. Tolerable? Not at all.

"Maybe he's more human than we're giving him credit for."

Sherlock turned his head back, resting his forefinger against his lips and thumb against his chin to hide the small smile that threatened to tug the corners of his mouth.

"I shouldn't go that far, John," he replied.

"Mycroft Holmes, world's best dad?" John suggested. "We could buy him a mug."

"You're daft. Tell me again why I put up with you?"

"Because you're madly in love with me and can't imagine a single moment without me?"

"Hmm," Sherlock said. "Yes. Good job you reminded me, I'd quite forgotten."

John chuckled quietly, then shifted, so Sherlock's arm was momentarily freed, then pinned again.

"Is your arm asleep?" he asked, sounding concerned.

"It was. Now it's only painful."

"Mmm. Good." John leaned more of his weight against Sherlock and the consulting detective feigned a groan. "I'm going back to sleep. Wake me when we get there. You should sleep too."

"You're always on me to sleep," Sherlock complained.

"No, sometimes I'm just on you," John replied.

Sherlock rolled his eyes, but this time couldn't keep the smile from appearing on his lips.

"Go to sleep, John, you're a menace to the civility of this carriage."

"You need to sleep, too, Sherlock. Your arm's asleep, so you're already part way there."

"Fine," Sherlock said, resting his head against John's. "Far be it for me to ignore the advice of a doctor."

John snorted.

"Yes, that will be the day," he replied, then closed his eyes again. Within minutes, he'd fallen back to sleep, his breathing deep and rhythmic, his body warm against Sherlock's, if somewhat uncomfortable.

Sherlock did not fall asleep for quite some time, almost content just to sit there – except for his numb arm – against John, but unable to still his mind. He had no real sense of what would happen now with Mycroft, and this was unpleasant. Not that he normally did, but he had seen a lot more of his brother than Mycroft had ever revealed before, even if he'd only seen that because Mycroft's hand had been forced. It changed some perceptions, but Sherlock was uncertain if he wanted that to mean he needed to change his attitude toward his brother.

He still very much did not want Mycroft's interference, nor his monitoring, nor his protection. He wondered now if he had more leverage with which to negotiate that.

Perhaps, he thought, he'd simply wait to see what happened. Mycroft had by and large left him alone, except for keeping a distant eye on him, for the past year and a half. Given this new situation with David, he may be occupied for quite some time, and Sherlock had a feeling there would be some repercussions for the exchange of Alessandra De Luca and David. Which was part of the reason he'd left with John in such a hurry – he had no desire to be part of those consequences.

Somewhere ahead of them, in the darkness, London lay waiting. Sherlock closed his eyes, leaning his head against John's again. Whatever came next, at very least, he wouldn't be alone, as evidenced by the doctor sleeping against him. And he'd done Mycroft a service, whether or not his brother would like to admit it, regardless of how it played out for Mycroft at higher levels. David would be returned safely, and Sherlock could use that as a bargaining chip, if need be. Carefully, since Mycroft would probably still be sore over the use of David for negotiation, but he would also be unlikely to forget that he now owed Sherlock.

The idea that his brother was in his debt, really in his debt, possibly for the first time, cheered Sherlock somewhat. It was nice to see the tables turned, and made it possible to relax somewhat was the train raced through the night, shifting gently on the tracks, lulling him toward sleep. Settling more closely against John, he closed his eyes, and let the motion and the warmth from John's body carry him away.

(End)