[Sherlock is on the floor, his back resting on a bed and his laptop balanced on his knees. Behind him, John is asleep; this much is obvious from the slow rising of his chest and the deep sound of his breathing. Sherlock speaks in a very low voice into the webcam, evidently trying not to wake John.]

"I had a fit this morning. I woke up very suddenly, probably early thirties, which was in the depth of my cocaine addiction. I felt like I was having terrible withdrawal, which I realise is ridiculous; withdrawal is partly physical, so I shouldn't have felt it. But then, it was probably psychosomatic. My body expected it because my brain told it I hadn't had cocaine in too long.

I shot out of bed, knocked over my bedside table. When I was still using, I had cut a hole in my mattress and created a small space where you could fit the bags, so I was on my knees tearing the bed sheets off, determined to get some, but I found that it had been sewn up.

By that time, John had heard that I was awake and he came to check on me. I didn't recognise him, of course, and I was convinced that he was a policeman come to arrest me for possession. Cocaine induced paranoia, completely ridiculous. Fortunately, I was in such a confused state that he was able to force me back into bed and be quiet long enough to make me listen to him. He brought me my laptop and said that I had a video on it that would explain everything. It did do that, but it didn't actually help.

Just because my mind knows that I have amnesia and haven't touched the drugs in a while doesn't mean that my body knows that. So I've spent the entire day being somewhat torn in two, my body telling me I need cocaine immediately and my mind telling me how stupid that is."

[John lets out a grunt and rolls over. Sherlock glances over his shoulder at him before he slides the laptop onto the bed. He stands with a grunt, picks the laptop up and takes it to the kitchen, where he rests it on the table and resettles himself on a chair. He now resumes talking at a more normal volume.]

"Better. Initially, John didn't want to leave me by myself. I nearly shouted at him, telling him I didn't need to be babied, but then I thought about the video I recorded, and realised we had that argument yesterday. It makes me wonder how repetitive his life is now. Do I say the same things, have the same arguments, every day?

Eventually I convinced him that I needed a shower and a bit of time to myself to sort things out in my head. Not that I needed to sort my head out- I've seen the video, I know precisely what is happening. But somehow, I don't think John accepts my hygiene as a reasonable reason to be out from under his supervision, so I had to speak to him on a level that he understood. He probably thinks I'm not as intelligent as I used to be now that I have amnesia, but I know that it isn't holding me back.

As John so kindly pointed out yesterday, I haven't changed much in the past twenty years, and I never forget more than that, so I still retain the thought processes that make me myself. Most cases don't take more than a day to solve, so I don't really see why I shouldn't return to working as a consulting detective. I'd like to continue this video diary for a little longer before I make any decisions, though. No sense rushing back to work if there's potentially a reason I shouldn't. In a week or two, I think I should have reconstructed enough of my story for me to make an informed decision."

[He pauses, picks up a dirty mug from the table and toys with it. He takes in a breath as though about to speak several times, but closes his mouth quickly and glares at the mug. Eventually he puts it down firmly and looks directly at the camera, intent on getting his story across fully.]

"I've been upset today. Not something I do often- as I said yesterday, I make a point of keeping myself above emotions. This situation is unusual though- twofold damage, really. I'm unstable because I think I'm addicted to cocaine and I'm uncertain because I'm amnesiac. It only makes sense that I would be a little more volatile than usual. John told me that he'd only ever seen me in a state like that once before: apparently we were in Devon after some hellhound, interesting case, but it isn't important right now. The point is, I saw something I knew logically couldn't exist, and it drove me to panic. Not quite the same situation, but I think I'm justified in experiencing a heightened emotional state in both instances.

Because of the state I've been in, John insisted I couldn't do anything useful today. He's spent hours trying to 'comfort me', which has been bizarre in the extreme. I didn't like to tell him how odd it was, because I believe a lot of the things he did were things he did to comfort me in the years I'm missing, and they are working. For example: he made me sit down and watch a James Bond film with him.

I've always objected to watching Bond films; ridiculous spy thrillers that are all action and no substance. There is nothing stimulating about them. But John assures me that he did once succeed in making me sit down and watch several at once with him. I felt calmer after the film had finished, but it must be to do with the fact that my brain was shutting down from boredom, because I find it difficult to believe that John was entirely honest about us watching these films. He probably just wanted an excuse to watch them again.

Amongst John's bizarre calming-down techniques, we also explored my mind palace- and by that, I mean I explored it while he watched. He wanted to see if I had retained memories there, but it is in the state it should be if I was in my early thirties. We did an experiment on some of the sausages in the fridge, we sent inflammatory texts to Mycroft…

It felt like John was distracting me. In retrospect, he definitely was, but it was from my addiction. At the time, I thought it was from finding out about my past, and I wanted to test him. Yesterday, when he was explaining about Moriarty, he was talking about people that were cleverer than me and he definitely avoided mentioning someone, and I asked him about it, determined to see if he would lie.

"Nothing gets past you, does it?" He said, laughing, "Of course you wouldn't let amnesia get in the way of your genius. I never could hide things from you,"

"So, who were you talking about? Who is this third person that can outsmart me?" I pressed. He seemed to be dodging the question, but I wasn't going to let him keep distracting me from the matter at hand. An odd look passed over his face, as if he was debating something internally. Eventually he spoke, obviously putting in a lot of effort to keep his voice level.

"Irene Adler. You always called her 'The Woman', although I never figured out if that was a mark of respect or because you hated her so much you couldn't even say her name. She beat you, kept outsmarting you. You did outsmart her in the end, sort of trampled her into the dust actually, and she ended up somewhere in the East. At the time… at the time, I told you that she went to America and got herself into a witness protection program, because I didn't know how you'd react to the truth. I suppose it doesn't matter now, you don't remember her; the truth is, she was captured by a terrorist cell and executed. Even though you beat her in the end, she played you really well; I've never seen you pay so much attention to a woman,"

I shot him a sharp look at that last comment. I hope he wasn't suggesting I had had some sort of romantic attraction to her. Romance is just a distraction, it clouds a logical mind. Whatever his implications, I had no reason to doubt what he told me, though it's hardly useful information, particularly given that the woman is dead. Of course, he wouldn't allow us to linger on the subject, so he moved swiftly on to distracting me again.

By evening I managed to overcome my body's lesser desires and the withdrawal had more or less stopped. It left my mind clearer, so I could think straight. Unfortunately, I don't have much to think about apart from my amnesia, and it began stagnating in my head. It terrified me. I will wake up every morning of my life with no idea what's happening. What about when I become truly old, and I wake thinking that I'm twenty? How could anyone cope with that?"

[A panicked edge has crept into Sherlock's voice. His pupils have shrunk and his breathing is labored. He takes a moment to reflect on what is happening, draws in a deep breath, visibly calms down. He raises a shaking hand to his brow before continuing in a somewhat bitter tone.]

"My whole life has been dedicated to the pursuit of developing my mind. A great deal of young people grow up and are upset by what they perceive to be the pointlessness of life; I never experienced that, because as far as I am concerned, the 'point' of my life is very clear. I need to be moving forward, always. Now that has been taken away from me, and the pointlessness of everything has moved to the forefront of my mind. I can't have my thoughts any more. What else is there? I might as well have gone mad. I wish I had gone mad- at least then I wouldn't be aware of how awful my situation is.

There was only so long I could feel that way before John noticed. When he eventually asked me what was wrong, I told him. Probably in greater detail than I should, in fact. But if he has been assigned as my carer then he deserves to know what's wrong with me. He looked more upset than I felt. I don't think he can bear the thought that another person is suffering and he is unable to do anything about it. I suppose that's why he became a doctor.

I'm quite ashamed of what happened next, but it is of vital importance that I am as honest in this video diary as possible in order to build up an accurate idea of what is happening to me. I was lying in bed, when I was overwhelmed with anxiety. The only coherent thoughts I had were that I didn't want to fall asleep, and I didn't want to be alone. In the end, I got up. I intended to read a book in the living room, but then I could hear John breathing as he slept, and for some reason, I wanted to be near him. So, like some godforsaken three year old that's had a nightmare, I went into his room and crawled into bed with him, just so I could have some human contact.

He woke up, of course, and turned over blearily to look at me. He didn't seem perturbed- it's entirely possible that I do this fairly regularly, so he has come to expect this. Not a thought that particularly pleases me… anyway, I felt the need to make my position clear just in case John was unsure of my intentions.

"Too alarmed to sleep. Don't want to lose memories again, just needed to be near someone" I whispered. He nodded with his eyes still half-closed, and shuffled a bit closer to me, until we were almost touching. Initially I wasn't comfortable with the close contact, but John fell asleep again very quickly and it was more or less like having an enormous hot water bottle.

When Mycroft was younger, he got asthma attacks. They made him panic, and he couldn't breathe, and before the doctor could get to us, we had to fight to keep him breathing. Eventually Mummy discovered that the best way to keep him calm was to breathe very slowly and deeply herself, and hold Mycroft close to her. He would pick up her pattern of breathing, and it calmed him immensely.

I am neither a child nor an asthmatic, but I thought the theory might still apply. I lay very still and listened to John's breathing and tried to mimic it until eventually I matched his breaths unconsciously. We lay there for hours, and I was very relaxed. At least, my thoughts slowed down a little, and I was very warm and tired. Every time I thought I was about to drop off, my body would give a jerk and I would be wide awake again. I concluded that I wasn't going to fall asleep without chemical help, so I slid out of bed with the intention of taking some sleeping pills, when it occurred to me that I hadn't recorded a video of today, so I got my laptop- which brings today's entry to an end.

Now I am going to take these pills and, with some luck, have an adequate night's sleep. At least, as adequate as it ever will be, when I know I won't retain any memories in the morning."

[Sherlock breathes a deep sigh. He is evidently exhausted; his eyes are almost bruised-looking underneath, and his movements are sluggish and clumsy. He stands, simultaneously opening the medicine drawer behind him and reaching out a hand to end the video. Fade to black.]