John had been watching Sherlock rather intently ever since had sat down at the breakfast table. This wasn't odd – John was prone to watching Sherlock intently – but it was uncalled for. There were no body parts of any kind in the fridge at the moment; Sherlock had not insulted anyone vulnerable recently; he hadn't even put either of their lives in imminent danger for the past couple of weeks.
"What?" Sherlock said, finally.
A flicker of confusion flashed across John's face, replaced instantly with humor and… smugness? Likewise uncalled for, Sherlock was sure.
"Just thinking about you, is all."
"Thinking about me."
"How you always do these little tricks to impress people."
"What about them?" Sherlock asked.
"Well, they're quite something, taken all together. But, not all of them are things that take studying or genius to figure out. A lot of them are just a certain way of looking at the world. Only you could pull off all of your deductions, but I'm willing to bet that anyone moderately bright who cared could pull off some of them."
"I agree," said Sherlock. "In fact, I believe I've expressed exactly that sentiment to you before, in about as many words."
John rolled his eyes. "My point is, the research side of things is hard, but the underlying method is actually pretty easy to learn."
"And I assume you think you've mastered it?"
John paused. "Well, mastered it, no, not really. But I think I've got the general idea, yeah. Not about to solve any unsolvable cases, but I know that you were preoccupied when you got up this morning, probably about a case with something interesting involving fingerprint removal."
Sherlock chuckled at that. "And, tell me, John – How could you possibly know that?"
"Well, for one thing," said John, "you forgot to shave."
"So, preoccupied. Very clever, John."
"And the case involves someone named Barlow."
"My! How did you come to that conclusion?"
"I saw his name on an envelope," said John, gesturing. "You do basically everything online, so an envelope must be for a case."
"Very observant; I'm impressed. Anything else?"
"Well, the fridge is suddenly full of pineapple juice, which people have at various times used to remove their fingerprints. So, presumably this Barlow case involves someone removing their fingerprints."
"I see."
"You traveled somewhere yesterday, because you left your shoes in a way that looks like you were trying to let them dry, and it hasn't rained here recently."
"Naturally."
"And you're actually dressed for once, which leads me to think that you're expecting some important visitor soon."
"Anything else?"
"Well… I'm sure I could find more if I put my mind to it. But you get my point."
"I do. And I'm sorry to say that you have effectively demonstrated exactly the opposite."
John paused at that. "What do you mean?"
"Well… Let's just say that your deductions may not have been quite as complete as you believed them to be."
"You mean I was wrong."
"Yes. Almost incredibly so, in fact."
"Really, then," said John, and there was something else in his voice. Not smugness at all, but similar in tone. Sherlock mentally catalogued it for later reflection. "Please, enlighten me."
"Very well. Let's take the points in order: I didn't shave because I was out of shaving cream, and yours smells oppressively of sandalwood. I'm dressed because, worse luck, I have an appointment to have a tooth pulled today. You're right that I prefer to conduct my business online, but from time to time I need to interact with businesses which are less technologically adept; the Barlow Dental Clinic is one of them. Pineapple juice contains bromelain, an anti-inflammatory proteolytic enzyme which aids in reduction of oral inflammation, and hence helps prevents the swelling and bruising common following major dental work. Anyways, pineapple is rarely used for fingerprint removal anymore; surgery is both more reliable, and far more permanent. I've written several blog posts on the subject, which no doubt you haven't bothered to read."
Sherlock was expecting a snappy comeback – he'd meant the last line as a bit of an opening jab, after all, something to start up the banter they always had when there was nothing more interesting going on – but none was forthcoming. Instead, John simply nodded in that way of his (disappointed, yet not surprised – but not quite the one that meant that Sherlock had crossed a clear line or was being otherwise unreasonable), said something non-committal, and went back to drinking his coffee.
Quicker than he had been drinking it before, Sherlock noted, which meant he was no longer interested in lingering in Sherlock's company. And he wasn't going anywhere at the moment (not with those socks) which meant the change of mood was due to Sherlock's jab – which in turn meant that he'd overstepped, somehow, after all.
Sherlock didn't see how. John hadn't read his blog, and he never did, even though Sherlock read his. It had come up before, playfully. It wasn't that John hadn't bothered to read it, it was that he couldn't be bothered to read it, because it was all very obscure and apparently of no use to anyone normal. That was typically how that joke went.
And the look that John had given him was not the one he gave Sherlock when Sherlock forgot to pull his punches. It was a derivate, but clearly distinct, and one that Sherlock only saw very occasionally. Five times in recent memory, in fact; possibly more if he really dug around for it. Sherlock mentally listed them now, in the hope that they'd shed some light on the current situation.
Number 1: Two weeks ago, when John had been very unsurprisingly dumped by his latest girlfriend. Not particularly applicable.
Number 2: Three days before that, when they'd both had the misfortune of running into Mycroft. Mycroft brought out such a variety of unsavory emotions in people that that was likely no help either.
Number 3: January, when Sherlock had (correctly) second-guessed one of John's medical pronouncements. The look had lingered, then, even after Sherlock had made it quite clear that not every doctor could be an expert in rare Amazonian toxins.
Number 4: Late December; Mycroft again. He'd made one of his obnoxious comments about Sherlock's skill, with a passing jab at John for comparison. Still less biting than most of what Sherlock would dish out himself, which was puzzling.
Number 5: Mycroft again, and once again disagreeable, but not particularly hostile.
Comparisons between the situations were difficult. The first one, in particular, largely bucked the pattern, as it involved neither Sherlock nor his brother. None of them really crossed any social boundaries. All of them involved criticisms of John, but none of them made a fuss out of it.
Slowly, Sherlock's mind eliminated the impossible, until he was left with a clear negative image. Because the only common strand, the one thing each of those situations had in common was… indifference.
John had finished his coffee, and was collecting his things to leave.
Well, that wouldn't do at all.
Sherlock put on his best imitation of a particular one of John's smiles – that one that was not the slightest bit condescending, nor self-deprecating, but was just genuinely warm, somehow – the one John sometimes used on him when they'd just been running for their lives and were feeling invincible. It was a fairly poor imitation, he was sure, but it would have to do.
"Oh, but John?" he said, as casually as he could manage.
John glanced up, disinterested. "Yes?"
"You were right about the shoes."
Slowly, a smile bloomed on John's face, and Sherlock's own expression began to feel a little less like artifice. "I was?"
"Quite so. I couldn't have done better myself."
"You don't say. Guess I've learned a thing or two after all, then?"
"Most certainly you have."