Bound to Be Wrong
"Are you sure he's faking?"
"Yes," the other voice replied in a much less hushed tone. "The breaths aren't shallow and long enough." A soft touch at the wrist. "And...well...his pulse is too fast." The man adjusted his breathing accordingly, hoping neither of them would notice. He was barely beginning to smile as he marked this ruse as a success when a flashlight beam to the face promptly aborted it.
The patient opened his eyes to find two coated men staring down at him in annoyance. One, however, was white-coated, while the other wore a black mackintosh. "Hello, doctor," the patient said, addressing the whitey. Whitey clicked off his flashlight pen and traded it in for a clipboard sitting on the table.
"We have some questions to ask you regarding your mental status," he said. "Do you know why you are here?"
The patient shook his head, provoking a startled frown from the Mac-wearer. "Do you - " the doctor began, but his companion replaced his question with another: "Really, Sherlock?" An awkward pause ensued.
"You're talking to the doctor, yes?" the man asked. The visitors always threw that name around, yet it still bore no familiarity; though he could not remember his name, it was surely not that.
Both of them ignored this question, the doctor resting a hand on the Mac-wearer's shoulder. "I know it can be difficult when a friend suffers retrograde amnesia. But surely you, of all people, will understand the importance of determining the cause. Please wait to talk."
"Of course, of course!" the man assured him in a Cockney accent.
And so the interview went on. The doctor asked about symptoms such as double vision, loss of balance, and fatigue, which, worryingly, described the patient to a T. When he had finally reached the end of the sheaf, he set the clipboard aside and began to examine the man's face, noting the swelling and dilated pupils.
After he had finished he gave off a business-like sigh. "It's nothing the blood test didn't already show, but you appear to have overdosed on valium," he said. "Your friend, John, found you in a comatose state, still living in a crackhouse. While it's rare to experience such extensive memory loss, it's not unheard of."
What? The man felt the pit of his stomach clench. "I'm...a junkie?"
The two men shared a look of mutual understanding. "We'd best not get into that now," the doctor replied. "As Lestrade here tells me, your drug use has been partly motivated by the need to investigate crimes. You were - are - a detective."
A detective...now that made intuitive sense. "I'm a detective," the man recapped. "British. Willing to go to extraordinary, almost inhumane, lengths. Do I have a family?"
"...and lastly, you should know that I'm your brother Mycroft."
"Sherrlock," the man slowly annunciated. The stiff-lipped bureaucrat from before confirmed the name with a - was that condescending? - smile.
"It's understandable that your head should be a bit...fuzzy," he said. "But it's really quite simple: Scotland Yard consults you for their most impenetrable cases, my job is to keep you, dear brother, in check."
On a brain rather than gut level, this was not challenging to grasp. "Sherlock" was merely searching for that click, that feeling of puzzle pieces coming together. That feeling that the world, if only for a brief instant, made sense. But there had been no such click. This "Sherlock" didn't sound the least bit like him, even down to the esoteric Victorian-sounding name.
"Are you sure you've got the right man?" the patient pressed. "Does your brother have a twi-"
"No," Mycroft interrupted unsmilingly.
Sherlock knew it was irrational to doubt his own brother's vouch, but perhaps this flaw could come naturally even to a detective. "This does not sound like a case of amnesia," he simply observed.
Sherlock's alleged friend "John" dropped in later that day, seemingly to test the waters - see what remained of their camaraderie.
Of course, before he'd even passed the threshold Sherlock had started to dissect him with his eyes. This was the deeply-ingrained habit that had prepared him for the revelation that he was a detective. Still, his brain was using an algorithm he only half understood. His subconscious seemed to shout all the important details at him, his conscious mind then fitting them together into a seamless story.
All of Sherlock's deductions occurred in the span of about three seconds. In the next span of two minutes, not a word was uttered between them, John sitting in his chair and giving Sherlock not so much a once-over as a twice-over.
Finally Sherlock couldn't take it anymore. And besides, he felt almost like the doctor wanted him to prove himself. "I know a bit about you already," he said. "You're an army doctor who's been invalided home from Afghanistan. You have a brother who's worried about you, but you won't go to him for help because you don't approve of him—possibly because he's an alcoholic, more likely because he left his wife."
John smiled lukewarmly. "How'd you know?" he asked. His reaction was so muted that Sherlock suspected he was humoring him, but he explained the deductions anyway.
"Brilliant," John said quietly. He paused awkwardly. "The past week's been tough," he confessed at last. "Almost tougher than...well, nevermind that now." Another mechanical smile, but his lips curled back downwards the second he stopped putting effort into it.
The other man shook his head at John chastisingly, and simply said, "I barely know you but I do know you're lying." To which John's response was a defeated shrug, but this time, no smile.
They sat in this suffocating silence for another thirty seconds before Sherlock's compassion got the better of him. He got the feeling his former self had been rather more talkative, and that this was a hard adjustment for the doctor. "What can I do to make you more comfortable?" he asked.
Rather than at least a front of gratitude, John's face displayed only shock. "W-well, first of all! You barely sound like yourself anymore." A frown that, judging by his wrinkles, seemed the doctor's default expression. "And this is coming naturally to you?!"
The other man shrugged. "As naturally as...anything I've done, I suppose. Maybe I have changed, but I'm already landed with a reputation - there'd be no point in deception."
"We have to find out how else you've changed," John declared. "We know your deductive skills are still intact, but...bloody hell, you could be a completely different person." He raised his eyebrows and nodded. "It wouldn't be surprise me." Sherlock smiled his old tight-lipped smile, proving that even default expressions could appear unnatural. Other than growing haggard, he had not physically changed since the overdose.
"Oh dear, tearing up again, aren't I?" The self-proclaimed landlady had captured Sherlock's hand in her own and continued to caress it creepily with her thumb. "It's like losing you a second time: your old boyfriend John is devastated, Mary's devastated...even Mrs. Turner. Poor, poor Sherlock…." Stroke.
Sherlock realized he had already mentally checked John off as heterosexual based on his clothes, grooming, and subconscious eye saccades, but now unchecked this box without hesitation. With so little data to work from, some of his deductions were bound to be wrong.