Disclaimer: I do not own ACD's characters or the BBC's adaptation. I am not a medical professional and the only knowledge I have on this subject is through basic research and personal experience. There is no established relationship in this story. Title taken from Arcade Fire's "Une Année Sans Lumiere (A Year Without Light)."
"John, where's my phone?"
That was the first time I noticed something wrong. Being so often in the company of Sherlock Holmes one tends to pick up some of his talents, and I became quite the amateur at deduction myself. "Where's my phone." Three simple words that were anything but. Had he said, "Have you seen my phone," I would have paid little attention. "Have you seen my phone" denotes a temporary misplacement, but "Where is my phone," hints that the object in question is utterly lost. The first odd thing was that Sherlock Holmes never loses anything. The second odd thing was that the phone was in my jacket pocket—the precise place he had put it a few hours earlier.
"Sherlock?" I pulled the phone out of my pocket and held it out. "You gave it to me a few hours ago, remember?" He opened his mouth, then closed it again and stared at the phone with a burning gaze.
"Yes, of course," he replied, snatching the phone from my hand. He examined and pocketed it before making a beeline for his room. Confused as to what had just happened, I ignored it at first. I wrote it off as simple carelessness. I even entertained the thought, as painful as it was to me, that it could possibly be drugs. But I pushed these thoughts away and allowed myself to ignore it for the time being.
The second incident was during a case in which a young woman named Sharon had been kidnapped and murdered. Typical case, but virtually no evidence, which was the reason we were called in. Sherlock danced around the body making silent observations as Lestrade filled me in on the technical details of the case.
"So Cheryl was coming from –"
"Sharon," I corrected him, shooting an apologetic glance at Lestrade for Sherlock's indifference to personal niceties toward the victim.
"Right," he paused. "Sharon." He shook his head and continued deducing. At this I took note. Usually when he would disregard a victim's name he had no shame in it and continued on as if I had said nothing. This time he seemed actually put off by the fact that he had mistaken the name.
"…and even more so, to create an alibi of sorts, the killer called Cheryl's boss to –"
"Sherlock!" I pulled him out of his stream of consciousness. He blinked at me.
"What, John?" He snapped, irritated that I would dare interrupt him.
"It's Sharon, not Cheryl." I studied his reaction.
"Yes, of course!" He spit, clearly vexed. "Does it matter?" He continued the rest of the evening in a petulant state, snapping at anyone who would even breathe.
A few more similar incidents followed, all with basically the same premise. Sherlock would misplace trivial things, forget where he was or why he was at a certain place, put the kettle on and then rush back when it would start screaming, perplexed as to how it got there. Diagnoses swam through my head, but nothing was concrete. I feared the worst and decided I should talk to him about it.
"Sherlock, I think we need to talk," I approached him one morning over breakfast. He looked down at me over his tea mug. "I've been noticing some strange things going on with you lately. You really haven't been your usual self. You've been sort of…slow and forgetful. Do you know what I mean?" He diverted his eyes and stared at the window.
"No," he said through tight lips, obviously disgruntled.
"No, what?" I asked. "No you don't know what I mean?"
"No," he repeated. He swiveled in his chair to look at me. His green eyes pierced my skin and I could feel ice in his voice. "No, John. No, nothing is wrong. No, I will not see a doctor. But 'no' is such a negative word, isn't it?" His tone became more cool and sarcastic. "Yes, John. Yes, I have everything under control, as always. Yes, I want you to leave me alone. Yes, I want you to stay out of my business." His words cut me, but I tried to push through even still.
"Sherlock, is it drugs? I won't be angry. I'll be disappointed as hell, sure. And of course as a medical professional I'll lecture you to death about how you're poisoning your body and most of all your mind, but I just want to know. Just tell me what's wrong."
"Of course I bloody well know!" The silverware leapt as his fist came crashing down on the table. "You think I don't see what's happening, John? You think I don't have one thousand explanations for this already? Brain tumour, schizophrenia, the list goes on! I go places and I forget why I'm there, I lose things in the most idiotic of places!" He dug his forehead into his palms and ground his teeth.
"Sherlock," I whispered, unsure of how to react to his sudden emotional outburst. His stoic visage was rarely broken, and when it was it hardly was because of anything as serious as this.
"Fix me, John," Sherlock looked suddenly at me, his eyes raw and slightly puffy. He grabbed my hand. "You're a doctor. What's wrong with me?"
"Well," I fidgeted, "have you been having headaches? Memory gaps that last several minutes, or even hours? Problems walking or balancing? Hallucinations?"
"No, none of that."
"Well Sherlock you know I can't fix you, and you'll need to see a specialist definitely, but I do have one suspicion as to what this might be." I desperately wanted not to tell him my thought. Anything but this, I pleaded internally.
"Just tell me, John."
"Well since you don't have many cognitive symptoms, it seems most likely, well it doesn't seem likely at all considering your age, but cases this young aren't unheard of –"
"Early Onset Dementia," Sherlock cracked.
"Well, yes," I admitted. "That was my initial thought."
"Was?" Sherlock looked up, slightly hopeful.
"Is," I shook my head. "It is my initial thought. It's the only thing that makes sense, even though it makes very little sense."
"When you've eliminated the impossible, whatever remains, however improbable, must be the truth," he looked away.
"Woah, don't think like that," I reached out my hand to him. He pulled away slightly at first, but then slid his hand into my touch. "I don't know anything for sure. Like I said, you'll have to go see other, more specialized doctors, and dementia can only be properly diagnosed post-mortem, but we'll see what some psychological tests say. Okay?" He looked at me and he looked scared. I saw right proper fear in Sherlock Holmes' eyes, which is something I did not see often. I could tell he trusted me and I wanted nothing more than to fix whatever was wrong with him. He was an ass almost all of the time, but his mind was his greatest treasure and I could sense his trepidation at the possibility of losing it.
"Okay," he smiled, and for a moment I thought that maybe I could help him through this. What did I know; I was only a silly old doctor. Maybe it was a brain tumor after all and could be easily removed by surgery. Maybe it was just stress, maybe we were overreacting. Whatever it was, I was certain I could help. I could be there for him and comfort him and be the friend he always needed.
Maybe.
