This was by far not the first incredibly simple deduction he had made in his lifetime. Many a truth had been reached by a single glance, or a swift touch, or even a brief sniff. Some had been so laughably obvious that it was hard for him not to be distracted by the prospect of a deeper meaning. A few times he had entertained the idea of a human who appeared simple through perfectly assembled personas of normality, a hidden intellect taking advantage of the cover of averageness, but as of yet the only example had been Moriarty. Too many people were too easy, one-dimensional cutouts who were of no interest. He craved a difficult problem, when so many were solved in the blink of an icy gray eye.
He may have doubted himself before, briefly, but another quick scan of the puzzle always provided a solid confirmation of his reasonings. Now that Moriarty had been solved, he searched elsewhere, hoping to find another who would throw him off guard. Someone to constantly set him off balance, give him a reason to stay sharp. John, of course, usually provided an interesting paradox to be studied, but that was precisely it. No matter how hard his mind worked, fitting pieces together with a logic intensely precise, he could not find an answer. So when he was alone and in danger of a relapse, he would pour over John's every action- a mind so utterly compassionate yet willing to kill for a man he'd known for less than a day?- in an attempt to stay sane. Yes, John was an extraordinary problem indeed. On the outside, so normal and average, so boring. On the inside, one of the most confusing men he'd ever met in his life. And he was never confused, not without a usually quick and always inevitable correction.
In the back of his mind, he knew he would never solve John, and if he was as honest with himself as he should be, he would admit that he didn't want to. After his puzzle was solved and neatly compartmentalized, what could possibly keep him together? It wouldn't matter anyway. Just as he thought he might make headway, John would do or say something that forced him to start over. And that was good, because attempting to solve John was a dangerous thing. The longer he spent trying to unravel the man, the less sense it made and the more he crossed into a realm of madness he had left behind years ago. It was rather unfortunate, he supposed, that the one person who was a constant in his life- other than his brother- was just past the point of his understanding.
Sherlock Holmes needed a challenge, preferably one he could beat. John was unsolvable, and thus was a last resort. One that he had grown increasingly dependent upon in the last few months.
Moriarty's empire had collapsed and was attempting to pull itself from the rubble. The crime rate in London and around the world had dropped substantially, and the influx of interesting crimes had become a few serial murders and the stealing of some sort of rather meaningless artifact.
Sherlock needed John right now more than he had in a long time.
That was why his mind was scrambling to piece together the situation, and reeling at the implications of the data in front of him. Yes, things were usually simple for the consulting detective, but sometimes the simplest deductions were the hardest to accept.
A small dent in the doorway to the kitchen, by the floor. At a height that suggests some sort of object pulled behind the person who had recently passed through, deep enough to imply a hurried forgetfulness. Someone had rounded the corner quickly and hit the doorjamb with whatever they were pulling behind them. The lack of further dents, even around the corner to the hallway where the front door was, which turned sharply and suddenly. After the first impact, they were more careful. Obviously, they weren't looking to be detected. The unnatural tidiness of a certain area of the den, a spot of clarity in the midst of the mess of papers and experiments that had been forgotten and left to either grow out of control or die. The rearranged plugs at the room's sole outlet. The cold and forgotten toast and jam placed haphazardly on the counter. The darkened fireplace that had always been lit in the mornings, no matter what had happened the night before.
All of these were glaringly obvious, but what made this entirely impossible were the empty drawers of the bedroom upstairs, and the carefully stripped and remade bed, and the absolutely sterile bathroom.
This wasn't even a deduction. It was obvious fact, laid right before his eyes. And yet it twisted in his mind like an imagined solution, intangible and unreal.
John was gone.
No, he had left.
There had to be some other explanation to consider, something he was missing, a sign of a struggle or a carefully constructed cover to throw him off track. Something had to explain it, this horrible staged place that couldn't be their flat, just couldn't be, there was no way John left because he would never leave him and Sherlock knew about the limp and the tremors and the nightmares that had slowly lost their power over the man, and this was not possible. Not even considering what had happened recently, when John had found his needles which Sherlock hadn't used or planned on using and never wanted to use when John was around, and there was an argument, a bad argument, and an angry John leaving to sleep at Sarah's, on the bed this time, and Sherlock wasn't entirely sure how that even happened-
Think! His mind screamed, think! And he tried, oh, he tried, but he was racing at five hundred miles an hour and it didn't even feel the way it was supposed to, not the way it always had when he really kicked in, all rush and fizz and a pounding thrill that filled his soul and made him realize that he had one, however deep it was hidden, and John had helped him find it. John, who had come home late from Sarah's yesterday to find Sherlock staring at a pile of plastic bags and white powder and small bottles, and syringes that he'd pick-pocketed off a doctor who had passed him on his way to John's office one late night. John, who had simply stood there while Sherlock steepled and folded his fingers in turn, again and again, using his hands to hide himself away the way he hadn't with John since the third day he had known him.
John, who hadn't even said a word in the fifteen minutes and thirty-seven seconds they had simply been there and Sherlock had tried to place and gauge the tension while John was as frustratingly blank as he'd ever been. John who had silently walked up the stairs to his room, his footsteps somehow heavy and soft simultaneously and his hand smoothly sliding along the banister, and Sherlock who had left to wander London and dispose of the powders and needles before coming back at five in the morning and retiring to his room.
John, who was gone.
Gone. Gone, gone, gone gone gone. The word repeated in Sherlock's mind, blocking all of his thoughts and derailing his logic, the very same logic he depended upon to get him through life, the very same logic that John had almost soothed with his presence and his acceptance of the world and the idea that you can't know everything, though Sherlock Holmes did. Or he tried. Sherlock couldn't think with the word filling his head, his logic wouldn't accept it when it applied to the one person who didn't quite understand him but didn't need to. Gone! The voice shouted, sounding far too much like panic. This didn't make sense, it didn't fit, and no matter how many times he turned it on its side and its head and every way he could, he simply couldn't understand it. So he worked faster. Somewhere in the chaos he wished for Moriarty. He wished for an enemy, someone he could blame, some problem he could solve and fix and then John would be right back where he was supposed to be, in his now- empty chair or by his computer typing up another infernal blog, or even where he'd never been before but should be, in Sherlock's hair and his arms and his lips. He should be where he had been unknowingly for a long time, deep within Sherlock, in a part of him that had long lay dormant, a part that many had threatened to burn out of him but only one could. And now, only one had.
He worked. He wouldn't stop, he couldn't bring himself to stop, because that would be giving up John and, by extension, a substantial part of himself. He moved on autopilot, searching for signs that could confirm anything other than what part of him said was an inevitable conclusion. He violently buried that thought under deduction after deduction, process after process, observation after observation, until it became a small twinge in his chest, possibly the strangest thing he'd ever felt. After he was certain he'd seen the entire first floor five, six times, he stormed up the stairs, barely hearing any sound he made. There has to be something, there's always something! He turned the old handle to John's door once, twice, before he could manage to get it open again, bursting into the room and stopping short to glance around. There must have been something he missed. His gaze flickered over the bed and then returned to it steadily.
The world stopped moving. He blinked slowly, and it was somehow still there, mocking him.
A folded note was almost completely hidden under the military-precise pleat of the sheets.
Sherlock staggered his way to the piece of paper, the little composure he had maintained evaporating as he approached it. He reached for it and his knees gave out, and he kneeled at the side of the bed, reaching for the note with a trembling hand. He held it gingerly at an arm's length, as if he expected a bomb to go off the instant he opened it. He wasn't certain that he wouldn't accept that if it were true.
He managed to force his hands to unfold the sheet of paper, doubled twice and neatly despite the signs of John's hurry. Two words were printed neatly in the top left hand corner, John's handwriting as completely familiar to Sherlock as his own.
I'm sorry.
And with those two small words written on what should have been an insignificant piece of paper, Sherlock broke.
He was downstairs again, and he was pushing aside a long expired jar of olives, reaching for the false bottom he had built into one of the lower cabinets when he'd moved in, and he was scrambling for purchase on the edge and then, and then he was pulling it away and throwing it behind him, grasping for the small bottle inside and the bag of sterilized equipment he'd neglected to gather that night that John had come home. Was that really yesterday? No, that was forever ago. That didn't happen. It wouldn't have ever happened if he could stop his hands from shaking as he filled a syringe with liquid, too much of it, and tried to get as much as he could out of what was left because too much was not enough. He was leaning back, tipping over the bottle and quickly righting it again before he could lose any more of what little he had left. He was falling briefly, then turning to lean against another cabinet, and he was plunging the needle into his arm for the first time since he had stumbled into Sherlock's life, the impossible, paradoxical man with the army tags and the kind, amazed, fascinated smile. The man who Sherlock, against all his instincts and his beliefs, had come to depend on unhealthily. He was tipping his head back and pushing the plunger and just holding it there for a minute before pulling it out, feeling an effect already. And then he was gasping and letting the syringe fall to the floor, closing his eyes to the vaguely familiar thrill of a rush, not the one he got on cases and definitely not the one he felt with John, but one that was close enough. He knew that in a bit, he'd be able to forget the world.
And maybe, if he tried hard enough, he could forget John Watson.
