There are footsteps in the corridor. For a moment, I consider the possibility that the cleaners have returned, but I know they never do. That means it must be someone else, and I am not supposed to be here. Only staying behind for a moment, I told the lecturer, and that was hours ago. Thankfully I never switched on the lights in the main room. I quickly flick the switch in the little side room, close the door apart from a tiny gap, and hope that whoever it is will pass without noticing.

The footsteps stop outside the door of the classroom. The door opens, and two men step inside. They switch on the main lights and I press myself against the wall behind the side door. The light streams in through the reinforced glass in the door, and I know that if I move I will be discovered. I hear the shorter of the two men say, "You're the one that's going to die here".

In one instant, I go from worried to petrified. I shrink further into my corner and try not to breathe. The taller of the two men, however, doesn't seem to be the slightest bit worried. He only sounds amused when he says, "No I won't".

I haven't really taken much notice of the two up to this point, but I can't help but notice that the taller man is a striking figure. He is impeccably dressed, but his dark hair is much longer than current fashion dictates, and combined with his long coat and self-assured, almost arrogant stance this gives him a definite Byronic air. The other man is grey, really grey and mousy all over. There is nothing remarkable about him, other than that he seems to be in control of the scene which is now beginning to unfold in front of me.

The two men sit down, and begin to talk. It's a strange conversation, and I don't catch all of it. It reminds me of watching two chess players – the pauses in between carry almost as much meaning as the words that are spoken. In fact, the grey man is doing almost all the talking, while his opponent just watches him. The grey man (did he mention cab driver?) puts something small that I can't see on the table in front of him, and then a moment later puts down something else. He pushes one of the objects towards the tall man, and I can see it is a small glass bottle, with a pill inside. He then begins to challenge the other man to make a decision, to choose a pill that could potentially kill him.

I have been watching the other man, as I can see his face perfectly from where I am standing. He seems completely unmoved, even amused by everything that has so far happened. Then the grey man apparently makes a mistake: he calls him stupid. The tall man's face hardens and he suddenly seems to take on the challenge. I cannot hear everything that he is saying but he appears to be telling the cab driver's life's story from just looking at his face and clothes. He's very quick and incredibly observant, and I can see the logic of the story developing as each observation is slotted in place.

I realise there is nothing commonplace about this man, and I feel slightly unbalanced watching him. I find myself being drawn into the scene, almost moving forward to get a better view and be able to hear more, until I suddenly realise what I am doing and check myself. When I recover my composure and look out again the grey man is holding a gun.

Do I run out? Do I stay hidden?I have become rooted to the spot, not knowing what to do next, and terrified by the thought that I am about to witness a murder that I could prevent only by putting myself in mortal danger. The tall man, however, appears to be enjoying himself. He is actually asking the grey man to shoot the gun at him. I close my eyes, not wanting to be part of what will happen next, unable to act, but there is no gunshot. When I open my eyes again there is a small flame at the end of the gun, and the tall man is smiling smugly.

For a moment, all the tension seems to leave the room. The tall man stands up resolutely and is about to leave the room when something the grey man says changes his mind. I watch in horror as the two proceed with their deadly game, but now merely to prove some kind of point. This time, I know I have to do something. As the tall man is about to take his pill, I take a deep breath and start to push open the door. Then, everything happens at once. There is a sound like a gunshot some way off, and of breaking glass close by. The grey man falls to the floor. The tall man runs across the room to look at the window. Blood spreads over the floor where the grey man is lying.

I quickly move back to where I had been standing, trying to blend into the background and wishing I was somewhere else. I am shaking all over. Surely, any moment now people will start to come into the room, somebody is going to open this door, and I will be discovered.

But the door stays closed, and the corridor stays silent, and the tall man is occupied with the dying man on the floor. I can hear him talking loudly, and there is a moan of pain from the dying cab driver.

"The name!" the tall man shouts, and I can see he is actually standing on the dying man's shoulder, hurting him to extract this information he so desperately wants. The man on the floor lets out a final unintelligible wail, and then everything goes quiet. The tall man leaves the room and walks away, and I realise that I have been given a window of time to escape.

I run out of the room, down the corridor, down the rear stairs to the back door which I know the cleaners sometimes leave unlocked. Five minutes later I am outside, shaking uncontrollably, walking as quickly as I can away from the building, away from that dreadful scene, back to my room three streets away. I collapse on the bed and for a while all I can do is lie there, and try to unsee some of the things I have seen today, unhear some of the things I have heard this evening. I cannot. And through my muddled thoughts a name keeps flashing by – Sherlock Holmes. That is what the cab driver called this stranger. It is an odd name, and I am not even sure I have heard it right.

When the shaking subsides, and I am left feeling drained and empty, I get up and find some food. Then I switch on my computer, pull up the search engine and type in that name.

-oooOooo-

Two weeks later, and it feels like my life has been turned upside down. I am not sure what is happening, but I cannot get the events of that night out of my head. More than anything, I cannot get himout of my head. This Sherlock Holmes is taking over my waking life and, more worryingly, my sleepless nights too. I have done my research – he calls himself a consulting detective, whatever that may be, and his contact details are freely available on his website. He lives with a Doctor John Watson at 221B Baker Street. They are not, apparently, gay. According to the doctor's blog, he is incredible, and as far as I can make out he's single. I have no intention to get in touch, yet I cannot ignore the first impression that he has made, and the fact that his face keeps flashing in front of my eyes.

I am all too familiar with my own nature – submissive, always looking for that strong dominant person, but mostly these men turn out to be either stupid or abusive. There is a string of failed relationships to prove it. Recently, I have settled on a single existence which is suiting me well. But there is no denying that I am being inexorably drawn to this man, to the point of obsession. I have tried to shake it off and get on with my life, but I am struggling. I also have started to have coffee in the café on Baker Street.

His landlady visits there regularly, and I have heard her speak sometimes about what happens at 221B to the owner of the place. It would be incredible even if only half of it were true. On the other hand, everything that she has said ties in with what Dr Watson is writing on his blog, so I guess chances are it is all real. Sherlock Holmes himself, meanwhile, is much harder to observe. He is either at home or driving off in a black cab, so the only glimpses I get are of him on the pavement.

Although these are brief, they are enough to confirm what I already guessed the first time I saw him – he cuts a very imposing figure, and the Byronic air seems to hang naturally around him. He is handsome, but in a very preoccupied way, his mind obviously focused on whatever case he is working on. Dr Watson rarely leaves his side. Compared to Mr. Holmes, he looks decidedly ordinary. I wonder how they became so inseparable as they seem an unlikely pairing.

None of this is helping me shake my obsession, which is in fact only getting worse. I am still only working part-time in the science section at the college, and this means I have plenty of spare time on my hands. Unfortunately, it also means that money is tight. This afternoon I am once again seated at the window of Speedy's, with a coffee that I am hoping will last me for an hour or so.

The café is quiet, so that when Mrs Hudson arrives I can hear what she says to the owner perfectly. She is complaining about the mess in the flat, the science experiments spread all around the rooms, and the state of the fridge. I am not sure I believe her claim that it has a jar of eyeballs in it. Then the door of the flat next door opens, and Sherlock Holmes steps out, alone this time. He hails a cab and heads off.

"Off to Bart's again, I'm sure", says Mrs Hudson. "He's always going there. John never likes to go with him, unless it's strictly necessary. He says some of his experiments are too macabre".

Like the eyeballs in the fridge, I think to myself. But my ears have pricked up at the mention of the name Bart's. That must be St Bartholomew's Hospital, where one of my old school friends is currently doing an internship. They all call it that, I guess the real name is just too much of a mouthful. I send her a text on the off chance that she knows in which part of the hospital Mr Holmes spends his time. While I wait for an answer I make my way there – by tube in my case, and even that is eating a hole in the budget. Maybe next time I'll walk.

Lara doesn't know anything about Sherlock Holmes so that means he is not in her department. She is covering most of Outpatients, but although that takes out a large chunk of the hospital it still leaves me with a very big area to cover. Since I have done well so far in getting information just by having coffees I make my way to the main canteen, and sit down with a cup of tea to think.

Macabre experiments, Mrs Hudson said. Now nobody would be allowed to carry out experiments on hospital patients, so where could he be doing this? And if the jar of eyeballs is real, where would they have come from? I guess every hospital has its morgue, and this must be where Mr Holmes is staying. It doesn't help me much – I couldn't just walk into a place like that without attracting a lot of attention, which is not what I am after. To be honest, I don't even know myself what I actually want. To see him, I guess, for more than a brief moment. To be a fly on the wall for a little while, to catch a glimpse of his life. I figure that my best chance is the canteen, because he must get hungry at some point, and he doesn't strike me as the kind of person who'd take sandwiches.

-oooOooo-

After five days of spending most of my spare time in the Bart's canteen, I have still to catch a glimpse of Mr Holmes at the hospital. I am beginning to think that I'd be better off at Speedy's, because I did actually get to see him there. As I am about to call it a day two girls enter the canteen. The first girl is short and a little plump, with short dark hair, and dressed as an assistant. The second girl is similarly dressed, but she's taller and has long blonde hair tied back into a ponytail.

"But he's so not normal, Molly. I don't know what you see in him. Honestly, he never even eats!" the first girl giggles.

The second girl forces a convincing smile, but there is something sad about her. The girls get their food and sit down some three tables away from me.

"Surely there are better blokes around Bart's? There's some really nice guys in IT you know, good looking ones too. You should go up there one day, just get away from the morgue and that weirdo".

The second girl, Molly, nods bravely. "Thanks", she says, "I'll remember that". She doesn't look convinced. "Sherlock's not as bad as you think you know", she says after a while. "He's just really clever, and I don't think he always knows what he's saying".

"What, with the stuff he gets up to?" the first girl blurts out, "whipping corpses in the morgue? What's all that about!"

Molly looks away, and inadvertently catches my eye. She seems nice. I can tell I am not the only one who is slightly obsessive. I smile at her.

"Listen", her friend says, "the only way you're ever going to get him interested in you is as a specimen".

Well, that settles it. I am obviously wasting my time here. Just like me to be waiting in a canteen for somebody that doesn't eat. I put my coat on and make my way out of the hospital. Outside it is another cold, grey London day. I put my hands in my pockets as I walk against the wind to the nearest tube station. My right hand touches something unfamiliar – a little piece of card. In the pocket of my coat, which I have been wearing and other than that has been hanging behind me on the chair for the last two hours, a chair that I haven't left, is a piece of card. Carefully I take it out of my pocket to look at it. I stop dead as I read the note:

221B Baker Street. Tonight 20:00 GMT. SH.

-oooOooo-

As I make my way along Baker Street, the feeling of unease that has been hanging around me all afternoon solidifies into dread at the pit of my stomach. I have no idea what I am getting myself into, but I very much doubt that it will be a nice chat and a cup of tea. When I get to the door of the flat I hesitate. I could just turn around and go home, pretend I never got the note, and put the whole obsession thing behind me. Just as I have made up my mind that this would be the wisest thing to do, the door opens. Mrs Hudson stands in the doorway, smiling.

"Oh hello dear, I didn't hear you knock there. Sherlock did say that there was somebody at the door. Do come in".

I swallow hard – no going back now. I give her what must be a very forced smile and step through the doorway. She leads the way up the stairs and knocks briefly before opening the door.

"Boys, you've got a visitor!" she warbles as she shows me in. The door closes behind me.

The room I am standing in is cluttered with what seems to be a random selection of paperwork, scientific instruments, chemistry glassware, weaponry, and assorted other objects. There is what appears to be a wildebeest skull with headphones on one wall. On the mantelpiece another skull, human this time. Next to it a very sharp knife has been thrust into the woodwork, through what looks like a pile of letters. There is a sofa and a couple of easy chairs, although the sofa is mainly covered in paperwork. At a small desk sits Dr Watson with a laptop computer, looking at me quizzically. In one of the chairs is Sherlock Holmes, looking at, apparently, the wall. He is holding a violin in one hand, the bow in the other.

"Ah, Miss Woodford", he says, putting down the instrument. Never taking his eyes of the wall he points the bow to the chair opposite. "Sit down".

I sit down. Dr Watson appears to be waiting to be introduced, but Mr Holmes ignores him. Instead, he picks up a small pile of paperwork from the floor next to him. To my horror I recognise the top sheet. It is my CV. The shock on my face must have been all too clear, as a little smile flits across his face. He takes a brief look at the papers, then places them on his lap, sits back and looks at me. I feel very uncomfortable under that stare, wondering what he can see, how much of the stories on Dr Watson's blog are really true.

"So," he finally says, "Miss Adriane Woodford. 2:1 in chemistry at UCL, MSc Environmental science, good pass. Currently employed in a menial part-time position at Roland Kerr with no apparent ambition to achieve any more, or so your supervisor says. So far so tedious".

He puts the paperwork back on the floor and looks straight at me. "No skill in any of that – I followed you back to your apartment. Once I got the address the rest was child's play".

Before I can say anything he shifts, leaning forward, and says, "Three weeks ago, you witnessed a confrontation between two men in an empty classroom at the college, which ended in tragedy. How much did you see?"

I feel like a rabbit in the headlights of an ancoming car. "Eh, I… I was in the side room. I saw everything", I manage to blurt out.

He sits back again. "And since then, you have been spending all your spare time following me around. Badly."

Suddenly, Dr Watson interjects, "Sorry, Sherlock, are you saying she's been spying on you?"

Mr Holmes glances across to him and says, "As I said, badly". I cannot tell if Dr Watson is suppressing a curse or a giggle.

"Question is," Mr Holmes continues, "Why? You could have taken any evidence about that evening straight to the police, but chose not to. If you were intending to bribe me, you could not have picked a worse way to go about it. That means it's not about the taxi driver case. If you had a case of your own, you could have just knocked on the door – you know well enough where it is after spending the last two weeks drinking coffee at Speedy's. I might have said it was for personal reasons, but anyone who reads John's blog will know that I take no interest in romantic attachments and your CV credits you with a brain, so I would hope it was nothing as banal as that".

He pauses a moment to observe me. I don't know where to look, and settle on staring at his shoes.

"Yves Saint Laurent" he says.

I look up in confusion, thereby meeting his eyes. He gives a little satisfied nod. "In any case, I believe you have been listening in to Molly's conversations as well. I consider her a friend, by the way".

There is the distinct hint of a threat in his voice this time, and I realise that I have been unwittingly overstepping the mark. I am getting very worried about where all this is going.

"Now then, taking all that into account, you still came here tonight to make me an unusual proposition of a personal nature. Is that not so, Miss Woodford?"

I am caught completely off guard. He has managed to pinpoint the idea that has only half-formed in my head for the last few hours. An idea that I am not sure about at all. Yet he is sitting there, no doubt observing my panic, and calmly waiting for me to voice my crazy thought.

"In your own words", he says.

I realise that I have no choice, that there is no point in holding back, because he already knows what I am going to say. My voice sounds strange as I say, "I would like to offer you my body".

Dr Watson chokes on his tea. I look at Sherlock Holmes and add, "For scientific purposes".

For a moment it is quiet in the room, as Dr Watson recovers his composure, and I try to hide in my chair, without success. Mr Holmes hasn't moved, other than tilting his head back a little to study me.

"Yes" he finally says, slowly. "That could be extremely painful".

"I'm prepared for that", I mumble, studying some fluff on the chair.

"Look me in the eye while you say that again", he says. There is a sudden intensity to his voice. I look up and meet his gaze. He has the most extraordinary blue eyes. I swallow hard.

"I am prepared for that". If I was expecting any approval on that face, I am disappointed. Already he is miles ahead, thinking. "Good. Fine. Call me Sherlock."

Suddenly, Dr. Watson bursts out. "Wha – wait, Sherlock. You are not seriously considering doing this?"

Sherlock looks at him. "And why not? There is only so much data I can get out of dead tissue, and I need a control. Molly would never let me experiment on her and neither will you, at least not knowingly".

Dr. Watson stares at him. Then he looks at me. "But why? Why would she let you do that?"

"Oh come on, John. It's obvious. Submissive personality, shown by the tattoo on the back of her neck, which is specific to that particular kink, hard to miss really, and the obvious ease by which she can be intimidated".

"Anyone would be intimidated by you", John interjects, "it's a sign of being human".

Sherlock continues as if he hasn't heard him. "Dead-end job, no motivation to progress, with her level of education, says there is something missing. Someone of her disposition is always looking for someone to give her direction. I met her supervisor and he's a wet rag, so no luck there. A boyfriend then? Miss Woodford has had no lack of boyfriends in the last two years, but is currently confirmed single and has been so for the last six months, which according to some of her girlfriends is most unusual. Why? It must be easy to find a single dominant man, especially in a college environment in a technical department, even with some of the physical disadvantages that Miss Woodford has got."

It takes a moment for that comment to hit home. My outrage is drowned by the next series of observations.

"There are faint scars on parts of her body" – he points to my throat and neck, and my wrists – "clear signs of abuse, and judging by the age and size of the scars, from different men. She's got scared, then. But six months of being single have left her feeling the need to associate with a dominant male, without necessarily the wish for any emotional or sexual attachment. So, after her witnessing events at the College, and doing a little research of her own, she has decided that this person is me. Molly's friend gave her the perfect idea of how to get to what she wants. Am I right?"

I am still reeling from what he has just done, and some of the implications of what he's said. The insults. The fact that he has been contacting my friends and work colleagues. But it strikes me that he has got it exactly right. I can't trust my voice, so I nod my agreement.

"But that's pathological!" shouts Dr. Watson.

Sherlock Holmes shrugs. "Probably. But it suits me. Give her a medical John, I need to get my riding crop from Bart's". With that he jumps up, suddenly all action, puts on his coat and disappears out of the door.

After a while, Dr. Watson closes his mouth. "Right," he says. He looks at me, accusingly. "I hope to God that you know what you're doing. I consider him my friend, and Iwas trained by the military. Although at a guess I'd say he's more creative".

This time, the threat is open. I suddenly feel the need to justify myself, after having been firstly so openly exposed and humiliated, and now threatened. I pass Dr. Watson the piece of card.

"I never intended to let it get this far. I was content just to watch him. I was summoned".

He looks at the card and a faint "sheesh" escapes his lips. "Out of all the people you could mess with, you chose Sherlock Holmes. I think you will find you've bitten off far more than you can chew".

We are both quiet for a moment. Then Dr. Watson says, "Well, we'd better get on with this medical".

He seems nice, approachable. I ask him why I would need one.

"He'd want to make sure you weren't going to drop dead in the middle of one of his experiments I guess. That would be inconvenient."

I am not sure he's joking.

"Wait here".

He goes upstairs and comes back with a small medical bag. He looks serious. "Listen, you need to be aware…" he hesitates. "He's not safe, you know. Sherlock". He hesitates again. "He… gets carried away sometimes. You need to be careful."

I want to tell him about what happened to the dying man in the College, but something holds me back. I just nod, "I know."

"Let's get on with this", he says, "I'll have a word with him. Call me John, by the way".

He gets me to take off my top. "Just the usual checks", he says, "heart, lungs, reaction, hearing, sight, balance, flexibility," he looks me over, "I don't think we need to worry about height and weight".

I brave a smile.

"I wouldn't worry too much about what he said about you, you know. He has a special knack for upsetting people. You look fine".

He gets out his stethoscope and listens to my breathing. "All clear so far", he says. "Cough for me". I cough. "Lungs are good, heart sounds fine". He gets out a light and shines it in my eyes. "Hey, contacts. Bad eyes?"

"Terrible," I say.

He looks in my ears. "No point doing a formal hearing test I guess. Ever had any problems with your hearing?" I shake my head. "Well, that's that then. Take your trousers off".

I must have looked blank.

"Reaction test, you know, on the knee tendon?"

I am giggling by this point. "Sorry", I say. I am now down to my pants and bra – not really what I was expecting when I nearly knocked on the door of 221B this evening. He tests my reactions, then makes me do some simple balance tests and I prove that I can still touch my toes.

"Well, that's it. You're in perfect health. You can get dressed now".

"Oh, I wouldn't bother," Sherlock says from the doorway. Goodness only knows how long he has been standing there. "You'd only have to take it all off again".

He strides in, riding crop in hand. The atmosphere in the room changes immediately. I can feel the hairs on the back of my neck stand up, and a small part of me observes how strange it is to have such a visceral reaction to somebody's presence. John looks at Sherlock.

"You're determined to go through with this, then?" he asks.

Sherlock's response is curt. "Clearly".

He glances across to John, realising that something has remained unsaid. "Problem?"

John looks incredulous, as if he can't believe Sherlock would really consider doing such a thing. Sherlock has straightened up, looking guarded, ready for an argument. For a moment, the two men are just staring at each other, neither speaking, weighing each other up. Then John visibly backs down, looking exasperated.

"No", he says, then, "Yes. Just one thing."

He looks at Sherlock again, who has not relaxed his stance.

"No permanent damage".

Sherlock looks a little bemused. "Why not?" he says.

This time, John is almost beyond words. "Because she's a bloody volunteer, that's why. Who you manoeuvred into volunteering, it seems".

Sherlock immediately glances over at me, eyes slightly narrowed, then back at John. "Fine", he says, sounding slightly peevish, "that shouldn't be a problem anyway. I'm only doing a bruising experiment."

He puts down the riding crop and hangs up his coat, then points to the bedroom. "Take everything else off and lie on the bed, face down."

John is looking very uncomfortable. "Right. I'm going out for a bit" he says, as he grabs his jacket and heads for the door.

"Don't stay out too long, Doctor", Sherlock calls after him, placing special emphasis on the final word, "I may have need for your services yet". Then he looks back at me, frowning slightly. "Still here?"

I make an unintelligible sound and force myself to walk to the bed. I take off my bra and pants and, as an afterthought, my socks. Then I lie down on my front, face turned towards the door, and wonder what is going to happen. I feel much more vulnerable now that John has gone and also aware that he has left Sherlock in a bad mood. I am beginning to worry that his attempt to protect me is only going to backfire.

Sherlock is still in the living room, and I can hear him moving about. It gives me a chance to look around the room. It is bare, untidy, and doesn't look used much. It is in complete contrast to the living room, which is obviously where everything happens. I wonder if he sleeps here at all. As I look across to the door again Sherlock enters carrying an assortment of things – notebook, pen, a small square thing, his phone, and the riding crop.

He puts everything on the cabinet in front of the window and sits down on the bed, next to me. Suddenly he is uncomfortably close, and I have to suppress an urge to move away. I am acutely aware of my own nudity. He quickly places one hand at the nape of my neck, holding me down.

"Lie still and don't scream", he says softly.

I wonder what he means when a searing pain shoots through my shoulder, travelling the length of my back and ending at my buttocks, as he scratches me with the nails of his other hand, hard and quickly. I gasp for breath as tears spring into my eyes and I can only suppress a scream by burying my face in the pillow.

"That", he says, calmly, "is for spying on me, which I sincerely hope you will never do again".

I can feel my skin burning where he has scratched, and am wondering whether I am bleeding. He stands up. "You will stay away from Molly Hooper", he says. "I can think of six other ways to make that point which are equally harmless, but considerably more painful. I hope I make myself clear".

I can only nod.

He walks back to the window and picks up the riding crop. "Right", he says. "Bruising experiment. You lie still and make as little noise as possible, I hit you with this".

He waves the riding crop about in a little comical gesture. His mood seems to have suddenly lifted, having made his point. I remember the quote about genius being one form of insanity, although I can't remember who said it.

"Cesare Lombroso, amongst others", Sherlock says from the window. "You should look him up, he makes good reading. And he understood about crime".

I resolve to stop all thought while in his presence in order to preserve some kind of privacy, as he can obviously mind read.

"No need to stop thinking, you just need to stop having a facial expression", he observes. I give up.

He walks over to the other side of the bed, where I can't see him. My guess is that's probably better, so I don't turn my head. No facial expression that way, either. He takes both my wrists and puts my arms over my head. Soft hands, I can't help but notice. Long fingers. It has been a long time since anyone has touched me anywhere, and I find my thoughts wandering. They are brought into sharp focus by the swoosh of the riding crop and the sharp slap of it connecting to my shoulder. I shriek as the white-hot pain registers. Tears, again.

Sherlock sighs audibly. "I said make as little noise as possible, not scream the place down", he says. "I'd rather not have to explain myself to Mrs Hudson, do you? Try and be ready next time".

I am still trying to catch my breath. The next lash, however, doesn't come. I turn my head to see what he is doing when I have calmed down a little. He is at the window, writing notes. Then he walks over with the little square thing, which turns out to be a magnifying glass. He bends over me and studies the welt. Very close again, I can feel the warmth of his body, and I am turning into a mess of mixed emotions. Facial expression, I try to remind myself, and I hope that he is too pre-occupied to notice. The slight superior smile when he briefly makes eye contact tells me otherwise. I turn my head back the other way.

Sherlock returns to the window, then walks back to the bed. "Again", he says.

This time, I bury my head in the pillow, close my eyes and clench my teeth. Whoosh, slap. I manage not to scream, much, and the sound is drowned by the pillow.

"Better", he says. Tears again as the pain registers, and I try to catch my breath. No sobbing, I tell myself, I will not be reduced to sobbing. The adrenalin is beginning to kick in and it helps. I am all too familiar with that feeling. I remember previous nights with previous men, and where some of the scars came from. I give a little compulsive shudder and push the memories away.

"Is this so very different, though?" Sherlock asks from the window.

I am beginning to understand why John Watson wears an expression of resignation around him. I nod, as I have no words at the moment.

"Why?" he asks.

I raise myself up on my elbows to look at him. He is still writing in his note book.

"You're not trying to kill me, for one", I manage.

He considers this a moment, files it for future reference. "Back down as you were. You need to lie still".

I flop back down, I've got the shakes anyway. I put my arms over my head again.

There is something cathartic about this. He is so obviously in complete control, even of my thoughts it seems, that I find myself entering a strangely calm state. The adrenalin certainly helps. By the fourth or fifth lash we have got into a pattern, and I can anticipate what will happen. Whoosh, slap, pain, tears, magnifying glass, notes.

Occasionally he takes a photograph with his phone. I am managing to control the screaming and am beginning to float. I have lost all feelings of self-consciousness or embarrassment. He has stopped speaking altogether, other than the cursory 'again' before each lash. He is working his way methodically down my back, accurately spacing out the lashes. I vaguely wonder what it looks like. I no longer have any sense of time and it feels like we have been here for hours, although that can't be, surely.

Lash follows lash, with just enough time in between for me to recover. My whole back is on fire, the left hand side still from the long scratch, the right from the welts that must be forming. He is getting close to my buttocks now and the pain is increasing with each lash. I find myself trying to calculate how many he will need to cover my buttock, how much more there is to endure, whether he is going to carry on down my legs. Whether he will have the sense to avoid my sex.

"Again", he says, again. I know where this one is going now, and I screw up my face before burying it in the pillow. Whoosh, slap. Right in the centre of my buttock, harder, it seems, than any of the ones that went before. The pain takes my breath away and I can't even scream. The tears flow freely, soaking the pillow, and I cannot suppress a sob. I'm not sure how much more I can take of this. My whole body is on fire, from the dull throbbing on my shoulders where he started, to the sharp pain of the latest lash. Magnifying glass. Notes. Then he walks up to the other side of the bed, the side where my face is.

"Finished", he says. "Stay where you are and don't move. I need to take the final observations in half an hour." With that, Sherlock leaves the room.

I am desperately thirsty, and I need the toilet. Everything hurts. I want to put my arms down. I want to look in the mirror. I wonder if he would notice if I got up for a moment.

"Don't move", comes his voice from the living room. I decide against it.

I must have dozed off for a while, because I wake up to the sound of John Watson shouting.

"Jesus Christ Sherlock, what the hell have you done to her!" He is standing in the bedroom, staring at me, fuming.

"I did the bruising experiment on her. That's what I said I would do," comes the calm voice from the lounge.

My body is still aching, but the burning has gone. I wonder how long I have been asleep. I can hear Sherlock get up and walk to the bedroom. He stops in the door opening. John points to my back.

"You're telling me that's a bruising experiment."

Sherlock looks across. "Well, the right side is. The left side was to balance things out".

John is only speechless for a moment. "But that's bloody torture!"

Sherlock just looks at him, unperturbed. "None of it is permanent, Doctor".

He walks over. Before John can say anything else, he is at the bed. What he does next takes me completely by surprise and by the sound of the "What the- ?" from John, I am not the only one. He quickly puts his fingers between my legs, touches my sex, and brings them back up again. It takes me a split second to realise what he is doing; I manage to suppress a "Hng". My shock and embarrassment are battling with a host of more confused emotions about what just happened. He steps back and holds his hand for John to see. His fingers are visibly wet.

"I'd say she rather enjoyed herself, wouldn't you?" he says as he walks out of the room. "She's all yours, Doctor. I did the final observations while she was asleep".

John is left standing in the room and I wonder who has been more embarrassed in the last few minutes, him or me. He clears his throat. I try to get up, but have stiffened up completely. It's probably the prompt he needed, as he quickly comes over to help me.

"Are you OK?" he asks.

I nod. He doesn't really know where to look. "It's fine, you know", I say, "I think I've become immune to being stared at".

"Oh", he says. "Right."

He's still not looking at me, and I guess he is not so immune, especially after what Sherlock has just done.

"Let me check your back".

I turn round so he can take a look. He checks the welts first, touching one of them gingerly. I flinch.

"Sorry. I need to get some cream for that".

He looks at the other side of my back and gives a little whistle.

"That's been bleeding quite a bit. I'll need to clean that up. God, I can't believe he did that." He sits back and looks at my face.

"Are you sure you're OK? You've taking a hell of a beating. Even if it was a scientific one".

I smile. I know I must look a mess, I dread to think what my face looks like after all the tears. But there's no getting away from the fact that I feel like I have been purged, like some great load of rubbish has been removed from my system, stuff that has been building up for months and years. I feel light, giddy almost, apart from the pain.

"I'm fine", I say, quietly. "He's incredible. I've never known anyone to have that much control".

John smirks. "Yeah. He's like that". He gets up. "Back in a minute", he says.

As he walks off I ask him for a glass of water. He steps back into the room, and mimes, "Did he not offer you anything?" while pointing towards the lounge and doing a 'drinks' gesture. I shake my head. He gives one final exasperated sigh, rolls his eyes and walks out.

He's away for a while, and I realise how much I need the toilet. With some effort I manage to get up. I look for something to cover myself with, but the thought of putting anything on over my aching back puts a shiver through me. In the end I decide it's a bit late to get self-conscious, so I walk into the lounge as I am. Sherlock is reading and takes no notice of my presence. I look around for the way to the toilet. He points towards a door at the back that I have just walked past, never even taking his eyes off the book.

"Over there". Always aware. I wonder what it must be like to have a mind like that.

When I come back in, John has returned from upstairs and is waiting with a bowl of water, a flannel and some cream. "Go lie back down," he says. "I'll sort you out".

It strikes me again that he's nice, and not for the first time in my life I wonder why I can't just be attracted to somebody like him, rather than always going for the ones who want to take leather whips – or worse – to me. He has put a glass of water in the bedroom, which I finish in a few gulps. I lie down and he gently cleans the long scratch on my back. Then he puts the cream on the welts, taking great care not to hurt me. It's nice, just lying there being cared for, and I feel myself drifting off. It takes me a little while to realise that he is finished when he clears his throat.

"That should do it", he says. He still looks worried. "You won't be able to wear anything much over that for a while", he says. "It needs to air. You need a light shirt or something."

I try to remember what I was wearing, and where I left the clothes.

"Hold on a moment," says John. He opens Sherlock's wardrobe. "I think the least he can do after all that is lend you a shirt, don't you?"

He picks out a white shirt and I put it on. It's baggy, but the fabric is cool on my skin. I gingerly put on my pants. The pain isn't too bad.

"Cup of tea?" John asks.

Not knowing what else to do next, I say yes.

We go back into the lounge. John clears a space on the sofa for me and I sit down carefully. Sherlock takes no notice at all, still reading. John goes off to the kitchen, and I have some time to look around the flat properly.

Frankly, it's a mess, but it's an interesting one. I'm not even sure what some of the stuff is for, and that's coming from a chemistry background. Some of the books on the shelves are ancient, and I vaguely wonder if Cesare Lombroso is among them. It all makes a strange contrast with the bits of modern technology that are scattered among everything else, and with the television in the corner. I don't think anyone could ever be bored in a room like this. I suppress an impulse to browse the book shelves, not sure whether that would be allowed.

John returns with tea tray holding three mugs of tea and a plate of biscuits. It is all very homely and the contrast with the previous events of the night couldn't be greater.

"There you go," he says, putting down my tea, "help yourself to biscuits."

I say thank you. "I didn't think I was coming here for tea and biscuits tonight."

"You didn't", Sherlock suddenly says from the corner. "All ready to go home, then?"

John puts down Sherlock's mug, but remains standing with his own. "Ehm, Sherlock," he begins, "you can't really send her home now. It's the middle of the night and she's in a right state."

Sherlock looks at me for a moment. "She seems all right to me." He hasn't mentioned the shirt.

"It's not done, Sherlock", continues John, "besides, I want to keep an eye on her. You'll have to sleep on the sofa tonight."

Sherlock raises an eyebrow as he looks at him. "Why can't you sleep on the sofa yourself? You're the one who wants to keep her here."

John sighs. "It wasn't me who beat her silly with a riding crop."

Sherlock picks up his tea, and says, "Fine". John sits down at the desk. I am quite taken aback by the amount of influence he has over Sherlock, who doesn't seem the kind of person to take any notice of anyone. Still, I am grateful not to have to make the journey back tonight, and even more grateful to be able to spend a little more time here. We drink our tea in silence, but it's a comfortable kind of silence, as if nothing more needs to be said. I am beginning to realise how tired I am, and have to suppress a yawn.

"Adri, get some sleep", says John from the desk. He nods his head in the direction of Sherlock's bedroom, "go on."

I look across to Sherlock. He is engrossed in his book again.

"Thank you", I say to John.

As I make my way to the bedroom, I realise the ease at which he just shortened my name. He's a smooth one, I think before lying down. Sleep doesn't take long to arrive.

I wake up in the middle of the night, momentarily disorientated. It is dark, but I feel strange bed, smell strange room, hear… nothing at all, which is never the case in my flat, there's always traffic. I move, and the pain as the sheet rubs against my skin brings all the memories of the previous evening flooding back. Sherlock. John. The riding crop.

I do a mental check on my body. Actually, I don't feel too bad. The skin on my back is still very tender, but other than that I feel OK. In fact, I am now wide awake, and feeling restless. The events of the evening have left me aroused and frustrated. I find it hard to shake the thought that Sherlock is next door, asleep on the sofa. I wonder what he looks like when he's sleeping. I feel a very strong urge to be close to him, tonight, maybe the only chance I will ever get. On a sudden impulse I get up and walk across to the door. I push it open quietly and slip into the lounge. There is light filtering in through the curtains, which haven't been closed completely. Enough to see by.

Softly I walk over to the sofa, satisfied that so far I haven't made a single noise. I can see Sherlock's outline, draped in a dressing gown, making an elegant silhouette in the darkness. I move closer to look at his face when I notice the glint of his eyes, very much awake, and following my every move.

"I know why you're here", he says.

I manage to mask my wobbly legs by pretending that I meant to kneel down on the floor next to him. I'm waiting for him to send me away, but he doesn't. Now or never, I tell myself. I take his left hand, not knowing what to say.

"Sherlock, … " I hesitate.

He says nothing, just watches me. I kiss his long fingers softly, expecting him to draw his hand away but he is just letting me carry on.

"I know you don't do this stuff", I say quietly, "but I… I wanted to give you something back. An experience."

He is still just watching me, looking beautiful in the soft light. I can't help myself. I touch his face, tracing the outline.

"Come to bed with me."

Any moment now, I think to myself, he is going to make some scathing remark and send you reeling. But the moment doesn't come, and still he hasn't moved. It occurs to me that he is just waiting to see what I will do, as if this is yet another interesting piece of research. If anything is going to happen I will need to take the lead. I take his hand again, stand up slowly and give him a little tug.

"Come."

It surprises me when he gets up. I lead him back to the bedroom, then stop and turn to have a look at him. He looks, if this is at all possible, uncertain, vulnerable, out of his depth. I wonder if he has ever done this before. I move closer to him, carefully, afraid that any wrong move will just scare him off. He is slightly taller than me and I look up into his eyes. Once again I touch his face, but this time I follow it with a kiss.

"You look beautiful."

I run my hand down his chest and undo his dressing gown. With both hands I gently push it off his shoulders, letting it slip to the floor. He is not wearing anything underneath. I can't help but wonder if he always sleeps naked, or whether this was a special occasion. I let the thought go – it doesn't matter. I kiss him again. He doesn't really respond, but he certainly does not pull away. Holding his hand, I lead him to the side of the bed.

"Lie down," I say gently.

The symmetry of the situation isn't lost on me, and it can't be lost on him. He lies down, still looking at me, while I take off my pants. Then I get on top of him, slowly, gently, so as not to break the moment. I cannot suppress a soft moan as I lower myself onto him and feel him penetrating me. I need him to touch me, but he is lying still, taking it in, just watching. I unbutton my shirt, moving slowly on him at the same time. Then I take his right hand, kiss the long fingers again, and place them on my breast.

He strokes my skin as I move, placing his other hand on my waist, committing to this experience that I must assume he has never had before. Slowly I increase the rhythm of my movements, taking my cue from his face, the slight opening of his mouth. His eyes have a faraway look but I feel close, as if I can feel what he feels, just for that moment. His grip on my waist is tightening as he is nearing his climax, and he closes his eyes as he comes, still holding onto me, penetrating deeply. I have been far too focused on his experience to worry about my own orgasm, but I find his release pushes me over the edge and I come, not quite as quietly.

We stay there a while, him looking at me, me looking back. He looks a little surprised. Finally, he just says, "Thank you".

I get off, legs wobbly again, and make my way to the bathroom to clean myself up. I'm not sure what to expect when I get back but Sherlock is still in the bed, staring up at the ceiling. I lie down next to him, but the pain on my back makes me flinch. He notices and rolls towards me, giving my shoulder a little push so I roll over, my back facing him. He traces the line of his scratch with his fingers, but doesn't touch the welts.

"John's a good doctor. It won't scar", he says.

No apology. I'm not sure I was expecting one. He rolls over and seems to fall asleep almost instantly. It takes me a while longer to find sleep again.

Daylight is coming in around the edges of the curtains when I open my eyes again. It must be early, as Sherlock is still asleep, still facing the other way. I can hear John pottering about the kitchen. I get dressed in what I can find in the room and head out through the kitchen into the lounge in search of my own clothes.

John says, "Good morning. Tea?"

I say yes, that would be nice. He is looking a little confused.

"I don't know where Sherlock's off to. He's left his coat."

"Ehm… ", I say. This could be awkward. "He's still in bed."

It takes a moment for the meaning of this to sink in. He just stands there, sugar pot in one hand, spoon in the other, look of complete disbelief on his face.

"Sorry?" he sounds incredulous.

"He's still in bed", I repeat.

"Wha- " He stops. "You mean… ", a slow grin spreads over his face. "you slept with Sherlock?"

"Ehm, yes", I say, seeing no point in denying it, "I hope that's OK."

He shakes his head, giving a little laugh. "Well I never. Good on you, Adri, good on you."

He turns round and continues to make the tea. I get my clothes and head off to the bathroom. John is still chuckling to himself.

Twenty minutes or so later Sherlock enters the room. He is fully dressed, and looking as cool and controlled as ever. He sits down and picks up his book.

"Morning Sherlock. Did you have a good night?" John asks.

"Fine, thank you", comes the short reply. It has do-not-enter signs all over it.

I am looking at John, who has a devious look on his face. He must have seen my pleading expression, as he gives me a wink and drops it.

"Tea?" he asks instead, still grinning though.

"Yes, thank you", Sherlock says from the corner.

John makes himself and me beans on toast. Sherlock doesn't eat. I'm just wondering what to do next when Mrs Hudson enters the room with a knock. She's a little surprised to still see me there.

"Oh", she says, stopping dead. She gives me a quizzical look. I'm glad that I'm not wearing Sherlock's shirt anymore. I get the feeling she's not as daft as she looks.

"There's a taxi at the door, Sherlock."

"That'll be Miss Woodford's", he says, eyes never leaving his book, "she wants to go home."

I wasn't aware that I did, but my mind has obviously been made up for me. I didn't book a taxi, either. There is an awkward silence. Mrs Hudson turns round and goes back downstairs.

"I'll leave you all to sort yourselves out, then", she says as she goes, looking not a little confused.

Nobody says anything for a while, then John gets up.

"Come on, I'll take you downstairs", he says. He looks across to Sherlock, "unless you want to, of course."

Sherlock completely ignores him. John looks pretty angry, but I just give him a smile. "It's OK, don't worry about it. I have things to do, anyway."

I am trying to pretend that I didn't see Sherlock briefly raise an eyebrow there. He's right though – I don't. I have no plans whatsoever. I get my coat and John opens the door. I consider saying goodbye to Sherlock, but he so obviously wants to be left alone that I just look back at him once more. To my surprise he meets my eye and gives me a brief nod. I try not to grin inanely. John takes me downstairs, and pays the taxi driver in advance. Then he looks at me.

"Goodbye, Miss Adriane Woodford. I hope we'll see more of you."

He shakes my hand. It's an odd gesture, considering everything that has happened in the last twenty-four hours. I can't think of anything to say back, other than "Thank you."

I get in the taxi, and 221B Baker Street disappears behind me.

There's one more thing I need to do. I get out my phone and text Sherlock.

"Don't feel ashamed of anything you did last night".

I just wanted to say it. I'm not sure what I expect, but within seconds there is a return text,

"I don't. SH". Then, a few minutes later, a second text. "Don't text me. I will contact you. SH".

Well, I think, I guess he knows where I live. I wonder if that is the last I will ever hear of him. On a whim, I ask the taxi driver to drop me off at the college instead of taking me home. I know I'm not meant to be working today, but there's a job going at UCL and I need to brush up my CV before I can apply. Time to sort out my life.