A/N: Because Sherlock always gets the last word ...
John drifted off to sleep, but Sherlock wasn't tired yet. The sex had been the slower, less exhausting kind, and he was still keyed up from both his climax and his temper tantrum earlier.
He could kill Mycroft.
When John was late coming home from work and stopped responding to his texts, it had been simple to deduce where he had gone. Now that Sherlock was calmer, he knew deep down that the idea of John selling him out for one of Mycroft's "benefits packages" was highly out of character for the principled doctor, but still, it wasn't impossible. Mycroft had "removed" other people from Sherlock's life whom he found objectionable. The fact that Mycroft had been able to purchase their obedience was a sign that they were unworthy company for Sherlock in the first place, but in his younger days he'd been quite an unworthy person, particularly when he'd decided the his life should be devoted to the pursuit of and abuse of narcotics.
He yawned quietly and rolled to his side, looking at John while he slept. Hmmm. This was new. Normally he couldn't bear to just lie in bed idly if he wasn't sleeping. But tonight it was all right. He even dared to reach out and toy with a lock of sandy blond hair. He wondered exactly what John had said to Mycroft. Obviously the correct assurances had been made because he was here. If Mycroft hadn't wanted John to be here, he would be most definitely someplace else. Somewhere far away. And Sherlock would find his own passport mysteriously missing from the flat. He'd have to jump through innumerable hoops before beginning his pursuit. Such was the way his brother operated.
Mycroft might always have the upper hand, but it didn't mean that Sherlock had to make it easy for him. Besides, his brother needed someone to push back. He would get mentally soft around the middle if he didn't. Sherlock smirked to himself. Already physically soft around the middle, the squidgy tosser.
He sighed and stretched gently, moving onto his back again, not wanting to disturb John, who was now snoring quite musically. He rolled the words around in his mind like a hard candy, trying to feel out any potential sharp edges, savouring the sweetness. I'm in love with you.
In love with you.
Curious. He still didn't understand what was happening. It was all very strange to him. Sherlock had scoffed at the notion of love for as long as he could remember. It wasn't something he seemed suited for at all. Living in a world where his behaviour and personality were met with mistrust, disdain, annoyance, and rejection, Sherlock had thought of civility as being the highest standard he could hope for. But love? Did he have something in him worth loving?
He frowned, looking harder at John as if the answer was written on his flesh. I keep asking why, John, and your answers aren't answers at all.
So perhaps the anxiety wasn't inexplicable after all. Sherlock was making the uncomfortable realization that he had entered a situation that went beyond deduction as he knew it. The things he needed to know couldn't be read in loose threads on a jacket or even in the expression on a person's face. It went deeper than that. To a realm of human behaviour that was beyond his ken. Before John, Sherlock had only comprehended the notions of sex and love as far as they affected and motivated behaviour and decision-making. Engaging in sexual behaviour had served to strengthen his knowledge of these motivations. Not to mention the fact that it was extraordinarily enjoyable with John. He was coming to crave the contact in a way that reminded him vaguely of another addiction that once ruled him. He acknowledged that if someone were to attempt to claim John's sexual attentions as their own, Sherlock would most certainly go to extreme lengths to prevent that from happening.
What lengths? How far would I go? Would I scheme? Most definitely. Would I kill? I would definitely consider it. Just the thought of someone else with him — red hot rage. Blinding. Would want to tear their throat out with my teeth. Why? Why would I go that far? There are other people to have sex with. It's something more than that. Is this the nasty business people always complain about where sex and love become inexorably intertwined?
John's snore crescendoed into a sputtering snort and Sherlock glared at him. "Shhh!" he hissed. "I'm thinking, John."
John grumbled nonsensically and rolled over onto his side. The snore resumed its normal pattern and Sherlock nodded, satisfied, resting his chin on his fingertips.
The criteria that John had set out to define the nature of love made sense to Sherlock. He felt all the same things. He wanted John around always, even when he was being slow and stupid and looking at Sherlock like he was speaking a foreign language. He'd never felt that way before. Usually he couldn't get away from people quickly enough when they tested his patience in that manner. Passion, well, yes. It was Sherlock's passion for John that had begun this whole debacle in the first place. Finally, sacrifice. Even thinking the word made Sherlock's pulse quicken. He would die for John. He'd been prepared to several times already. There was no question about it. John was essential. John must be protected at all costs.
Ugh, there was that sickly feeling in his stomach again. What was that? Sherlock concentrated harder, opening files and riffling through them, searching for the answer.
He had a weakness now. A soft spot, like an infant's fontanelle. A chink in the armour. Oh, that was unsettling. It was only a matter of time before it was discovered and exploited. He would have to immediately start running scenarios, determining the outcomes, and devising the most effective courses of action.
It's all right. This is a challenge. You need those. You'll just have to work a bit harder, that's all. Less time being bored, that's good. Yes, it's good.
He turned to his side again and looked at John, who was curled up with his back to Sherlock. He looked so vulnerable and fragile, though Sherlock knew the doctor was made of much stronger stuff. But still, everyone looked helpless in their sleep. Sherlock moved in closer, until his chest was pressed up against John's back. John murmured softly and unconsciously moved back against Sherlock, seeking his warmth.
Sherlock wrapped an arm around John's waist and let the other man snuggle back against him. What's this called again? Spooning, right? Yes. Quite nice, that.
He stretched his free arm across the pillow above both their heads and gently rested his cheek on the back of John's neck. John smelled good there. A natural concentration point for pheromones, of course.
"I love you, John," he murmured softly. Then he closed his eyes and began mentally constructing the first scenario. He had much work ahead of him. They would be coming for him and he had to be ready when they did.
A/N: I'm wrapping it up here. This was supposed to be a bit more light-hearted, but Sherlock got all thinky and a bit angsty on me and then it all seemed to tie in with some Reichenbach foreshadowing, so there you go. I might come back to this established relationship in the future, but this arc seems to tie up nicely here. Thanks for reading!