Where does one person end and another begin? Usually not a difficult question to answer as each mind is confined to the brain it inhabits, but as our ingenuity enables us to overcome the barriers nature would impose on us, so we discover there are unforeseen consequences.

Nietzsche famously said that when you gaze long into the abyss, the abyss gazes also into you. I'm not sure this is what he meant by it, but it fits. Physics predicts that you can't observe something without changing it, and as you exert an influence on it, so it responds by exerting one on you.

Not in any way a Valentines story, but it's finished, so it might as well go up.

-oOo-

"You can't seriously tell me that you actually believe in telepathy!"

"Sure. Why not?"

"Because it's stupid is why not! There's no scientific basis for it!!"

"Yes, there is."

"What!?!"

It was fun to watch. You could almost see the accumulation of punctuation in his growing agitation.

"Thoughts are nothing more than electrical signals in the brain, right?"

"Agreed."

"Wherever you have a changing electrical current, it creates a changing magnetic field."

"Oh, I see where you're going with this. It's rubbish."

"Give me one good reason."

"The current in the brain is measured in micro-amps. The magnetic field created would be minute."

"Birds migrate by sensing the Earth's magnetic field. That isn't so massive."

"It is by comparison. Besides, birds actually have magnets embedded in their brains, you don't. So, how would you go about sensing a changing magnetic field?"

"By induction of course. Change a magnetic field near to a conductor and it induces a current with the same pattern. The brain's a conductor. Has to be since it carries an electrical current."

"And as I just said, it's measurable in micro amps. The magnetic field would be too small to detect."

"It's big enough to measure with an E.E.G."

"I think they measure scalp potential or something similar with those. It's not the same!"

"There is a measurable magnetic field as well."

"Maybe close to the surface, but you don't have to go too deep before it practically vanishes. That inverse square law is a bitch! How the hell sensitive do you think your instruments would need to be to pick up a field at even a few centimetres?! Besides which, you'd need both brains oriented the same way before the signals would make any sense, even if you could pick them up!!!"

The exclamation marks were creeping back in. I needed to conclude this before he lost interest.

"So okay, natural telepathy is unlikely, but what about with a little help from technology?"

He gave me a sceptical sideways glance, but I had him hooked again. It was like playing a fish, and about as much fun. He could escape any time he put his mind to it. The trick was convincing him that he didn't want to.

"I'm listening," he said cautiously after I'd allowed the pause to stretch out for a while.

I had him alongside the boat now. Catch net in hand. Just ease it into the water.

"Well, like you said. The real problem is accurately sensing a weak field, and then creating a strong enough one to induce it into another brain. What I really need is to be able to generate massive currents and magnetic fields, for which I could do with a superconductor, and preferably one that will operate at body temperature."

"Ah! This all makes sense now. The free lunch, the tantalising conversation topic. You had me worried there for a minute."

"So what about it?"

Mike's department had recently discovered a method of making the world's first genuinely high-temperature super-conductive material. A ceramic polymer with a reported superconductivity threshold of one hundred and ten degrees Fahrenheit, or just over forty-three degrees Centigrade. The stuff was fiendishly difficult to make. Utilising a new molecular patterned adsorption catalyst under carefully controlled conditions, it could be grown, but extremely slowly. The catalyst had been manufactured painstakingly, molecule by molecule, using nano-robots, and would take years to produce in any appreciable quantity. What catalyst they had was busily making more of the super-conductive polymer, but again, it would take a painfully long time to produce more of the stuff.

Just about every department in the university had been romancing Mike in an effort to persuade him to hand over the small amount of polymer that existed. Following his press release and demonstration, just about every scientific journal in the world had written articles raving about the newest wonder material, and everyone wanted a piece of it. The military had thrown a budget his way bigger than the GNP of some small countries, and he was already tooling up to make more of the stuff, but then that would disappear into military research. The sample he had right now was about all there was that had even the slightest chance of making it into civilian hands.

I didn't know what anyone else had offered him, but Mike was that peculiar kind of idealist who was immune to any of the conventional forms of bribery. His reasons for accepting the military funding were more related to patriotism than greed, and I was pretty sure that nothing anyone had offered him so far had made even the slightest dent in his armour.

His real passion was the progress of science. His favourite quote, though he couldn't name its source, was that the only difference between science and science fiction was sufficiently advanced science. By offering him a way of actually achieving something that had so far only been realised in Hollywood, I was appealing more to his very active imagination and love of the amazing, than to his almost non-existent avarice.

"How do you propose to deal with the alignment issue?"

He was back in the room, his very able mind having chased through a whole lot of issues. This was where the real fight was going to take place, where I'd either land the biggest fish ever, or just have a 'one that got away' story.

"By referencing the autonomic functions in the base of the brain. They're similar enough in pattern, position and orientation in every subject I've looked at so far."

"How will you discriminate between brain waves and other electromagnetic effects?"

"Two sensor nets close to each other but at sufficiently different distances from the subject's brain. Subtract one from the other, and what you have left is brain activity. That and I want to use ultra-fine filaments to reduce the size of any eddy currents."

"Which is, I assume, why you can't use any more conventional superconducting material?"

"Yeah. For one, they're too brittle – they can't be formed into a fine enough lattice, or if they can, the lattice breaks when you bring it down to operating temperature. For another, the net needs to be brought close enough to the subject that it then quickly warms up above threshold."

"Not to mention the risk of cold burns. What shape will your sensor net be?"

The conversation degenerated into higher mathematics and scribbled formulae and diagrams on paper napkins. I fought to hide my smile. I had my fish.

-oOo-

The sensor net turned out to be a thing of exquisite beauty. The super-conductive polymer had an iridescent, multi-hued sheen to it, not unlike titanium oxide jewellery, and extruded into fine wires, and interwoven into the intricate Celtic knot arrangement that Mike's and my maths had suggested, the result wouldn't have looked out of place in a jeweller's display.

Initially, I'd experimented with a sort of net cap design, but the delicate filaments tangled too easily with the subjects' hair and made it impossible to be consistent in positioning. I could have shaved my subjects' heads, but in the long run, this would have limited the use of the device. My second idea had been to turn it into a necklace of sorts, with the primary and reference nets positioned concentrically.

Somewhat awkwardly, the net didn't work well under clothes. It was very delicate and mobile enough that even the slightest movement altered its reading. This meant it had to be worn on open shoulders and neck, with any long hair held out of the way. The unusual consequence of this particular requirement was that I didn't get any male volunteers in the trials. My lab was a little too cold to ask anyone to go shirtless for any length of time, and the only pieces of clothing that I could find which kept the head and shoulders free were women's tops and tee-shirts with scooped necklines. The men felt self-conscious enough about wearing what appeared to be a pretty feminine piece of jewellery, and when asked to wear an item of women's clothing as well, they all declined.

Which left me with one option as a test subject. She was a physics undergraduate and her name was Janice.

One thing I've struggled to understand is why there seems to be such a strong a negative correlation between the physical appearance of a young woman and her aptitude for physics. I'll be the first to admit that my experience in the matter is considerably less than exhaustive, but I still maintain that the size of my data set is large enough to show a significant pattern. Perhaps lack of physical attractiveness might influence a young lady to pursue interests in other areas other than romance, or perhaps the more highly intelligent make a deliberate effort to hide their appearance so they can be more readily appreciated for their intellect.

Whatever the reason, Janice was no exception to the rule. Her long dark hair seemed to spread out with a mind of its own and somehow contrived to look far worse when tied up into a bun or high ponytail than when it was loose. Janice also had poor complexion and very little chest development, which inclined her to complain about the necessity for wearing the low cut tops. She relented a little when she discovered I'd be wearing one as well, but this didn't so much diminish her acerbic wit as redirect it.

"I don't like pink," she told me on the day of our first experiment.

I'd bought two scoop necked tops, one in pink and the other in a deep royal blue. It didn't worry me much who wore what though, so I passed her the blue one. A little while later I was distracted by a flash and turned to find her smiling at the screen of her phone. She showed me the image, which inevitably was of me in pink, with chest shaved and the slightly heavier induction net already in place around my neck.

She arched an eyebrow in challenge, to which I shrugged. Knowing her, she'd be more likely to make a big thing of it if I made a fuss about it. I already had something of a reputation for eccentricity, so a little supporting evidence wouldn't be too great a price to pay for results.

In this I was correct. She posted it anyway, but without any great fanfare. I was subject to a few smirks and sniggers from the more puerile among the student body, but things settled down soon enough and no harm done. Unfortunately though, the results this minor inconvenience paid for were equally minor.

There was no doubt that the device worked, more or less. From the moment I switched the apparatus on, even at a low level, I was bombarded with thoughts and impressions, but they were such a jumbled mess I couldn't begin to make sense of them. It was like being at a crowded party with everyone talking far too loud, except that almost every voice I heard belonged to Janice.

Asking her to clear her mind, to focus on one thing only, to meditate, to try just about everything and anything I could think of to make sense of the cacophony, did nothing more than change the emphasis of different parts. One voice or another would quiet down, but then every other voice present would get just a little louder.

It was frustrating. We tried several hours a day, every day for nearly three weeks. I altered settings on the device, I tried to add filters, I increased the size of the two nets, but with no discernible effect. With Janice's permission, we tried the experiment while she slept – no results – with her drowsy from a mild sedative – just as many voices and just as loud, only slurred – we tried hypnotism, but Janice wasn't susceptible.

By the end of the third week, with both of us frustrated and dejected at our lack of progress, I thanked Janice for her efforts and let her get on with her life. If we'd shown more success, I think she'd have been more inclined to continue, but she'd been complaining of mild headaches after the sessions, and the lack of progress had worn away her resolve more swiftly than mine. Besides exam week was swiftly approaching, and her mind was refocusing on her studies.

I shut the machine down and headed up to the cafeteria for a coffee.

"Hey professor, nice, très chic, just like on Facebook. Taking a walk on the wild side, huh?"

I looked up into the eyes of someone who was as much the antithesis of Janice as it was possible to be. Long blond hair cascading from her shoulders in elegant waves, skin as clear and smooth as alabaster, ice blue eyes set in the most exquisitely beautiful face I'd ever seen. Alive but somehow vacant at the same time.

"I'm sorry?"

"I love your necklace," she said. "It's so different, and I think you are so brave to go out in public like that."

I looked down at myself to discover I hadn't thought to change out of the pink top, and I still had the induction net resting on my neck and shoulders. I might have been more embarrassed had my mind not been clamouring for my attention. Opposites, vacant eyes…

"I don't think I've seen you around," I said. "Do you study here?"

"Yeah, but over in the art department. I don't get science. I'm studying to be a beautician."

"I imagine it's a subject you know a great deal about," I managed a weak smile. Generally speaking, I'm not great with people, but in a pinch, I can hold my own, in my particular bumbling way.

"You're kind of sweet. I guess I'm going to have to get used to dealing with people like you if I work in a boutique though, aren't I? I mean do you go anywhere to get your hair done? Or your nails?"

The conversation was turning surreal. I suppose I can't blame her for thinking I was something I most certainly am not, but if she was jumping to conclusions, there was nothing to stop other people from doing the same. Eccentric I didn't mind, but I'd rather not be thought of as that unconventional a person.

"No, I don't. Listen, I have to get back to my lab. I don't suppose you'd be interested in coming and having a look? I have another necklace like this one, only a bit thinner. I'd be interested to see how it looks on you."

"Really? That would be so sweet." She was all teeth and smiles. "Yeah sure, why not?"

"Shouldn't you be in class right now, er, I'm sorry I don't know your name."

"It's Mandy. No, I have a free now. I guess you do too, or you'd be in a classroom somewhere."

"Yes, I er, I don't do much teaching at the moment. I have a particular experiment I'm working on, so someone else is taking my classes for a few weeks."

"Oh, that's so cool. So what is it you're studying? I mean jewellery and stuff doesn't seem at all sciencey."

We made our way out of the main corridors and down the stairs towards my subterranean lair. The basement rooms tended to be larger, which I preferred to having a window to look through.

"My current line of investigation is telepathy and telempathy."

"Oh cool! Is that like moving things with your mind and stuff?"

"Not quite. That would be telekinesis. Telepathy is more communicating with your mind. Telempathy is like it, except you communicate feelings instead of thoughts."

"Wow, that's so amazing! I didn't know you could do that!!"

"Well, that's the point. We can't at present, which is why I'm trying to see if it's possible. Here we are." I indicated a nondescript door part way down a nondescript corridor. "It's not much, but it's home – kind of."

I ushered her through the door and leant back on it, letting out a relieved sigh.

"What's up?" Mandy said looking around her, her eyes like a child's in a toyshop.

"It's just that I forgot what I was wearing when I went upstairs. I wouldn't want people to start drawing conclusions from seeing me wander about looking like this."

"I don't know. You look kind of cute." Again the megawatt smile.

"It's generous of you to say so. Here's the other necklace. Would you like to try it?"

"Sure." With a deft hand, she lifted her hair out of the way and turned her back on me. In her heels she wasn't much shorter than me, making the job of fastening it in place so much easier. She was already wearing a top that exposed as much of her upper body as might be considered decent, so there was a lot of skin available on which to arrange the sensor net.

"It's sticky," she said with a note of mild disgust.

"It's supposed to be," I replied. "The filament – the wire – is very fine. It has a tendency to bunch up which doesn't look so good, so I added something to make the surface a little tacky. It's perfectly clean, and it peels off easily enough. Mine's the same, look."

She reached out and touched the array sitting on my own chest and shoulders, then let me carry on arranging the sensor net on her. When I was done, she dropped her hair back down, and it somehow managed not to get tangled. I decided to leave it as it was and see if we could get by without tying it out of the way.

"There's a mirror in here if you want to look." It was actually an observation room with a two-way mirror, but she didn't need to know that.

Her eyes were wide. She lifted a hand to touch the sensor.

"It really is very delicate," I said intercepting her questing fingers. "Would you mind waiting here for a moment? I just need to check something in the other room."

I could probably have said anything I liked. All her attention was on her reflection and the way the delicate network of super-conductive wires looked about her neck.

Outside I started flicking switches, turning on instruments, computers, power supplies. Normally I'd use a check-list, but I'd done it so many times in the previous three weeks, I could have been half asleep and still done it right. Last switch and turn up the curr…

-oOo-

I was no longer in the lab surrounded by all the paraphernalia that made this particular experiment tick. Instead, I was looking into a mirror, and the face staring back at me belonged to Mandy.

"Oh my God," I said, only it was Mandy's lips that moved, Mandy's voice that made the sounds.

This wasn't supposed to happen. The sensor net was supposed to be passive. It had been in the first design when I'd tried to make the sensor into a cap rather than a necklace, but in its present form, it generated its own magnetic field in order to pick up the changes caused by the micro-currents running through the brain above it. I'd used currents as high as this with Janice without either of us experiencing any adverse effects, except maybe those headaches. This was unexpected though.

It's a long-standing concept in physics that you don't observe something without changing its nature, but this was excessive. I had to turn the machine off, but how. I couldn't see the switches around me to know when I'd found the right one. I couldn't even see myself to know if my hands were even moving. What if I ended up being trapped in this body?

A cold terror swept through me and I felt tears welling in my eyes. My hands, acting on autopilot, started fanning in front of my face – or rather Mandy's hands and Mandy's face. Perhaps she was in here with me. I tried thinking her name, but nothing came.

I made a conscious effort and stopped the hands from moving, Drawing in a deep breath, I felt both tears and terror subside. Then it struck me how much of a ditz I was being. If I was controlling Mandy, looking out through her eyes, moving her hands and lungs, then all I needed to do was step out of the observation room and turn the machinery off out there. Failing all else, I could simply unclasp the sensor net, although who knew what a sudden break in the link would do. No, we were too far down the rabbit hole to be taking stupid risks.

I turned and walked out the room, conscious of my bare shoulders, bare midriff, bare legs beneath the short skirt, of my feet perched almost on tiptoe in the high heels. Of the caress of hair down my back, of the jiggling weights on my chest, most of all of the absence between my legs.

The whole experience was sensuous in a most alarming way, and I felt a wave of unexpected pleasure wash through me. Knees weakening, I stopped to lean against the wall. Then taking a breath, I pulled the door open and stepped out into the familiar surroundings of my laboratory.

My own body was frozen in place where I'd been sitting scant moments ago. My hand suspended in the act of turning the dial that controlled the current. I couldn't help smiling. I really did look cute in that pink top with the induction net resting neatly on my own chest. You'd think a guy would look ridiculous dressed like that, but I looked kind of hot for an older guy.

My tongue came unbidden to my lips and I tasted lipstick. The unusual flavour brought me back to myself and I took the last few steps over to where my body sat.

Unusually, I found no difficulty in walking in the heels. It felt so weird, but kind of cool at the same time.

"Time to wake up Alice," I said to my immobile body. On impulse, I reached down and kissed myself on the lips. Soft, sensuous, a little scratchy, but it was afternoon. I usually had a fair growth of stubble coming through by this time.

I moved my hand off the dial. It was a little stiff, but not rigid.

"God, I hope this works," I muttered as I turned the dial smoothly to the left.

There was a disorienting blur of thoughts and perceptions and I was looking at the back of Mandy's head, where she was leaning in front of me. She staggered and collapsed against me. I grabbed hold of her and supported her until she managed to get her feet under her.

"How did I get here?" she asked. "I must have blanked out there for a moment, because…"

I wiped the back of my hand against my mouth and it came away with lipstick on it. I wiped it a couple more times while Mandy kept her back to me. I felt ashamed of having taken advantage of her, and anxious to hide the evidence of my indiscretion.

She turned to me. "What happened there? Do you know?"

"I'm not sure. It might have had something to do with my experiment. I'm going to have to think about things for a bit. Will you let me have my, er, my necklace back?"

She bit her lip, her mind apparently easily enough distracted by more important matters. "I was kind of hoping I could borrow it? You know just for a day? I have this date tonight, and I really think it looks good on me. Don't you?"

"Yeah sure, but er…"

"Please? I promise I'll take care of it, and I'll bring it back first thing tomorrow."

A mixture of thoughts and emotions fought for supremacy inside me. I thought of the experiments I could do testing the range of my equipment. I thought how wrong it would be to do anything more without talking to Mandy first. I thought that I hadn't decided to go ahead with any experiments yet, but why not keep my options open? Morality lost this time, but I like to think that at least part of it was because I wanted to do something nice for Mandy.

"Sure. Take really good care of it though. It's a one of a kind."

"Apart from yours, you mean?" She reached in and kissed me on the cheek. "Mmm, scratchy. I like a man with stubble." She wiped at the spot she'd kissed – more lipstick. "I'd better get going. I have a class in a few minutes."

"Sure. I'll see you tomorrow."

"Thanks, professor. You're the best."

With that she was gone, leaving me in a swirling mess of thoughts and feelings. What exactly had happened? I unclasped the induction net from my own neck and set it to one side. The vivid memory of being someone else was overwhelming, and I needed to do something to resist the temptation of doing it all again.

I turned to my notes and began reading from the beginning.

-oOo-

It was early evening by the time I finished reading through my journal. Ordinarily Janice would have come by after her last class in the middle of the afternoon, and we would have continued with the experiments, but since we'd agreed to stop after the morning's failure to achieve anything worthwhile, I'd had nothing to interrupt me. It did mean I'd managed to read through every last one of my notes though, and I had at least some idea of what had happened that afternoon.

It turns out, as is so often the case, that my first instincts had been right, the root of the problem lay with the redesign of the sensor and induction nets. As necklaces rather than skull caps, the nets needed to generate their own strong magnetic fields in order to function. This wasn't a problem in itself, partly because the zero resistance of superconductors made pretty much any current and any strength of magnetic field possible. I'd limited to safe levels initially, but then when things hadn't worked with Janice, I'd started tinkering.

No single modification had been dangerous. I'd incorporated limits and safeguards as best I could, and had been confident in my design. It wasn't until I checked through the whole set-up that afternoon that I realised a couple of these supposedly independent modifications affected one another in a rather dramatic way.

I'd somehow managed to create a positive feedback loop in the field current of both superconducting nets. The wave pattern that first superimposed Mandy's brain waves onto mine then took the combined pattern from mine and overlaid it on hers, switching back and forth a number of times over and increasing in strength each time until limited by the output of my power supply. We'd actually been lucky that the supply hadn't burned out in the process.

This seemed to answer how I'd ended up in Mandy's brain, looking out through her eyes, moving her limbs, but it didn't answer where she'd gone in the whole process, or why the same thing hadn't happened with Janice, who'd been subject to the same runaway signals.

This was where science turned to the age-old, tried and tested technique of making an educated guess or two. The next step would be to perform experiments to see whether or not the new hypothesis was right, but in the meantime, the guess would have to do.

It seemed reasonable to assume that the answer lay somewhere in the differences between my two subjects. Janice had been both highly intelligent and driven, compared to Mandy, who was closer to average on the IQ scale and far more passive in her manner. It was the latter difference rather than the former that seemed to hold the key. It explained why all I'd sensed from Janice was a constant stream of chatter as her overly active mind constantly reviewed all the different aspects of her life, reinforcing within itself all the little things that made her who she was. As a result, all she'd experienced from the experiment was a mild headache, possibly caused by the additional effort needed to reassert all her thoughts and memories against the induced changes from the device. Meanwhile, I'd received her jumbled mess of thoughts and been unable to make any sense of them.

Mandy's mind, by comparison, had been free-wheeling. Senses open, waiting for a new experience and ready to respond to it. It had been like a blank canvas, ready for my machine to transfer my consciousness onto it, and, apart from a few of her automatic responses to the experience, most of what had been going on in her mind had been me.

So where did she go? I suspected she'd still been there somewhere, underneath it all. Her consciousness suspended briefly while I took over.

So last question, what had happened to my body during the process? That was harder to explain, but, again based more on guesswork than concrete evidence, I had the idea that I'd actually existed in both minds at the same time, and that the feedback loop kept the two of us in sync. My two different perceptions of the world at that time would have created small amounts of interference which would have broken down my thought process, so I'd subconsciously blocked off the weaker of the two. Why that had been my own mind rather than Mandy's I don't know. Younger brain perhaps, or emptier, or filled with more exciting, new experiences. This was where my speculation found no handholds; nothing to suggest a reason.

I closed the last of my notebook files, and leaned back, staring across the lab at my equipment. The responsible thing now would be to shut everything down, rebuild the whole system so that the same feedback loop would be blocked.

I mean this could be dangerous couldn't it? It would be unethical to try again. Mandy hadn't given her permission to be part of this. I'd only tried it in the first place because I hadn't really expected it to work, because even if it had, I'd only expect to be able to pick up a stray thought or two, maybe speak a word or a short sentence into her head. It had been part idle curiosity, part a sense of fun. I'd never expected this, and to try again without first discussing it with Mandy and getting her approval would be wrong.

Wouldn't it?

The thing is, so many important advances in science happened through accident and providence. Fleming's discovery of penicillin, Newton's experience with the apple, Galileo's observation of the swinging chandelier in the cathedral. Sometimes you had to recognise when fate or good fortune handed you an opportunity.

Besides, it had been quite the rush.

It would only take a few minutes to build and install a current limiter for the power supply. It would stop any of the components from burning out or overheating, and it would mean that the induction fields wouldn't be as strong as earlier, which would mean safer conditions than the first time. It would be a little more involved, but I could also build a timer circuit that would gradually reduce the current after a few minutes. I could recreate the events from earlier under reduced conditions, and what would be the harm in that? Mandy was somewhere across town and wearing the sensor net right now, or at least she should be. I'd be able to test the range of the apparatus. I wouldn't have another chance like this.

Not my proudest moment I'll admit, but fortune favours the bold, or something like that.

It took a little longer than I'd anticipated. Once I'd built, tested and installed the additional circuitry, I had a minor crisis of conscience and decided to check the entire apparatus. If the results were likely to be as extreme as they had been earlier, I wanted to be as sure as possible that everything would be safe. Fortune also favours the prepared mind.

It was half past nine before I decided I was ready. Everything had been checked over and tested. One or two components were replaced that looked like they might have overheated a little in the previous run. Heat sinks were added here and there. At long last I settled into my chair with the induction net in place around my neck. I set the time for thirty seconds, which I estimated was the amount of time it had taken me in Mandy's body to figure out what was going on and do something about it.

I took a deep breath and flipped a switch.

-oOo-

I was lying on a bed with a heavy weight on top of me. There were posters on the walls and ceiling, suggesting a student room somewhere on campus. That was all the objective observation I could make before being swept up into the events of the moment, though.

A hand moved under my shirt – no, blouse – caressing my breast and sending shock-waves of intense pleasure coursing through me. I could feel the stubble of a chin rubbing against my neck, and my own fingers were tangled, mid-embrace, in a mass of longish hair.

I let out a gasp of pleasure as rough fingers brushed over my erect and over-sensitive areola.

The head moved up into my field of vision and I found myself looking into a face I vaguely recognised.

"You like that, do you baby?"

I answered by closing my grip on his hair and pulling him towards me. My lips met his as a new wave of pleasure overloaded my senses. A hand snaked up the inside of my thigh causing me to arch my back and bite my lip. Fingers slid over the top of my knickers and pulled them down. I could feel warm moistness in my crotch. It wasn't my usual equipment down there, but it was all stoked up and ready. I knew what I wanted in that moment, and again I arched my back to make it easier for him to ease my underclothes off.

His practised fingers slid up my thigh again, found their way between my labia, touched a particular, highly sensitive spot, drawing an involuntary squeal from my throat.

And I was back in the lab, breathing hard and sweating.

I stared at the timer. There was no way that had been all of thirty seconds just now, was there? There was certainly no way I could have prevented myself from what I did next. I'd designed the timer to go considerably higher than thirty seconds, working on the principle that one day I'd be able to extend trials into the minutes and even hours. I twisted the dial all the way around and flipped the switch.

His fingers were inside me, moving in and out rhythmically, causing me to respond. His Lips left mine and headed towards my breasts. I fumbled for a moment with the awkwardness of buttons on the wrong side, but managed to open my blouse by the time his questing tongue made its way to my left breast.

I had never known such intense longing, and I was utterly caught up in everything that was happening to me. I wanted this guy inside me in the worst way, and without consciously doing anything, I found my fingers reaching down to loosen his belt.

With a grin on his face, he reached for a little foil package sitting in plain sight on the night stand. The tiny niggling feeling that was my conscience subsided. If the condom had been out where Mandy could see it, then she'd been intending for this to go all the way, surely.

His practised movements told of considerable experience on his part. He slid out of his jeans and rolled the piece of latex over his little soldier. Part of me was alarmed and a little bit envious at how much larger it was than my own. Most of me was just excited at the prospect of feeling it inside me.

There was a tube of K.Y. on the night stand. as well, which I took and squirted a liberal amount into my hand. The lubricant gel was cool and silky smooth, unlike his little guy. With a tiny shock of realisation, it came to me that I was about to experience what was meant by 'ribbed for her pleasure.'

I opened my legs and guided him into place, the whole sensation totally alien and oddly familiar at the same time. A little adjustment and with a gentle but insistent push, he was in.

It felt amazing. He held himself away from me and looked down at me, grinning with enormous self-satisfaction. I could imagine the expression of surprise and delight on my own face, and lay back waiting for him to take control.

He didn't rush it. The movement started off slow and built in small increments over the next few minutes. I could feel a tension growing inside me, climbing higher and higher until it reached an almost unbearable level, before easing over the edge and running down the far side, filling me with wave after wave of intense pleasure. It happened again and again, several times over. I lost count. I heard myself screaming several times, but I don't recall it being in any way voluntary.

Eventually, on about my third or fourth time over the edge, and feeling as though I were losing all sense of identity, I felt a change in him, a growing tension which I managed to match so that he just brought me to my peak for a final time as he thrust himself into me for that last shuddering climax.

We lay in each other's arms, sweaty and entirely spent, breathing hard. My body was humming like a high tension cable, and for all my exhaustion, I felt more alive and alert than at any other time I could remember.

It only felt like a few seconds before he withdrew. He climbed off the bed, removing the protective sheath from his rapidly deflating monster, and heading for the bathroom. Typical of all men, he was out in seconds, by which time I was off the bed and feeling a need to clean up myself.

Typical of most men, he'd left the toilet seat up. It was a small enough thing to correct. Cleaning up took a while longer, and gave me an opportunity to investigate my borrowed anatomy, now highly sensitised and in need of no further stimulation.

By the time I was done and back in the bedroom, he was half dressed and hunting for his tee-shirt.

I stripped off the rest of my clothes and, naked apart from the necklace, slipped into the bed.

"Join me?" I asked trying for a soulful, seductive look.

"You know I would babe, but I have to be up for practice first thing tomorrow, and if I stay we won't get much sleep."

That was where I knew him from. Steven Jensen. Spoilt little rich kid, former student of mine and member of the university's football team. Probably more through wealth than talent, I thought, perhaps a little uncharitably, but he'd not struck me as being particularly committed to anything other than sexual conquest when I'd taught him.

I wasn't sure if he was referring to a night filled with similar activities, or just that the bed was a little narrow for two to share comfortably. It didn't matter.

I climbed back out of bed and picked up one of his shoes. He was already tying the laces on the other. I handed it to him, and draped myself over him as he put it on.

He stood as soon as he was done, swinging me round in front of him. He flashed me one of his dazzling smiles and reached in to kiss me long and hard, then slapping me on my bare backside, he pushed himself away and reached for the door.

"I'll call you," he said with a level of insincerity that even I could sense, and with that he was gone.

-oOo-

It seems ridiculous to say, but the moment the door closed, I felt abandoned. I'd just enjoyed the most amazing sex, I was filled and fizzing with the afterglow, and I wanted to share the experience.

Not sit down and chat over a cup of coffee share. More sort of snuggle together and inhabit the sensations and the memories of what had just happened while he – yes, he – held me close and did the same.

Experiences mean more when they're shared, even when the extent of the sharing is little more than being together and inhabiting your own private thoughts while your someone special does the same next to you.

Being on my own meant that all those wonderful sensations felt out of place. It was a bit like being halfway through listening to a favourite song and having someone turn off the radio. It was jarring, and it robbed me of almost all the pleasure of that recent experience.

I found a silk dressing gown hanging on a hook behind the bedroom door, and I slipped it on. The soft, smooth material felt alive against my hyper sensitised skin, both delighting me and revolting me at the same time. It just felt so oddly wrong to be enjoying these sensations with no-one else around.

Contentment gave way to full-blown frustration. I wanted to be lying peacefully in my lover's arms, and now in his absence, I needed to be active and doing something. I yanked the sheets off the bed and balled them up, then went in search of some new ones.

This was ludicrous. This wasn't even my life. Not my body, not my boyfriend even, so why did I care so much? Or at all?

The weirdness of the thought struck me on two levels. First that I should even think in terms of having a boyfriend. Second that it should seem so natural and right, even if he was a rat bastard.

I found the laundry cupboard and raided it, made the bed then set about clearing up Mandy's room. She wasn't particularly untidy – certainly no more so than I was under normal circumstances, but I needed to vent my frustration on something, so I added dirty clothes to the sheets in the laundry hamper, I cleared up the odd mug, plate and bowl from the various little nooks and crannies around the apartment, and washed them up. I dug out a spray can of polish and a duster and drifted around the place freshening everything up. I didn't know how much longer I had on the timer, and was rather hoping it would run out sometime soon.

Eventually, I'd done all I could find to do around the apartment, and I was still feeling bent out of shape. I set the bath running and put the kettle on. A quick search through the kitchen cupboards turned up what I was looking for. However much diamonds may be a girl's best friend, chocolate has always been a lot more affordable, and a very close second. Mandy had a few sachets of low cal hot chocolate stashed away, and I figured this would be a good time to use one of them.

I was on the verge of disrobing and stepping into the steaming water when the thought occurred to me that maybe getting wet with the sensor net in place wasn't such a great idea. I yanked out the bath plug, and headed for bed, mug of steaming chocolate in hand.

At least the chocolate helped. Not much, but a bit. I finished it off in short order, washed up the mug and brushed my teeth.

Wide awake as I was, with the clock still reading the wrong side of ten o'clock, I had nothing left to do. There was a book on the night stand., but I wouldn't have the opportunity to finish it, nor would I particularly enjoy it, I was sure, so instead I turned out the lights, snuggled down and waited, staring into the dark.

With nothing to do but reflect, I began to realise just what I'd done and it settled on me with an oppressive weight. I hadn't been thinking, obviously, but even reacting to circumstances as I had, I should have realised somewhere how much of an invasion this was. They'd have to come up with a whole new branch of law to cover what I'd done. I tried to imagine what it must have been like from Mandy's point of view, how she would react when she found out. It turned my blood to ice just thinking about it.

The first time had been just speculation – see what would happen with a new test subject sort of thing. I'd never expected it to work, and had been astonished when it had, and to the extent it had. The second had been premeditated and purely selfish. Although I had been conscientious enough to limit the connection, that didn't change the fact that I had deliberately planned to steal thirty seconds of someone's life; to invade their mind and body without their consent or knowledge. The third time had been responding to a ravenous hunger I didn't know I possessed until that moment, but it was still theft and a rape of the mind.

I felt sick. I closed my eyes, feeling tears squeeze out from between my borrowed eyelids. Lying in the dark, I was acutely aware of all the differences, big and small, of inhabiting this body. Long hair trapped under my shoulders, the awkwardness of breasts preventing me from lying on my front with any comfort, the broadness of my hips and narrowness of my waist making lying on my side feel so different. Then there were the residual feelings from the sex. My legs felt a couple of miles apart, as though someone had stuffed a bowling ball between them – not so much discomfort as awareness.

I longed to give this body back to its rightful owner. All the differences heightened my sense of invasion, and I wanted to undo it all. I wanted to be back in my own body and away from all the constant reminders of this thing that I had done. I wanted to give Mandy back her life, now. To minimise, if such a term even vaguely applied now, the harm.

And yet all I could do was wait. Wait for the timer to count down to the end. Potentially I could head into my offices and use Mandy's hand to dial down the current as I had the first time, but it would probably take me longer to get there than was left on the timer, and what would Mandy think if she suddenly woke up in the middle of nowhere?

Even if I did make it in time, how would I talk my way past the night guard?

Even if I could do that, how would I explain to Mandy what she was doing back at my place?

No. Better to wait. I focused on the darkness and stillness, and let them fill my mind.

-oOo-

I woke up with a stiff neck, sitting awkwardly in my chair and shivering in the cold. I didn't remember switching back here, so I must have dozed off in Mandy's body before the timer ran out.

The equipment was still humming gently, so I stood, stretched and set about shutting everything down. The clock on my computer said it was about four thirty, which explained the chill at least. My head was all muzzy, my mouth felt and tasted like the bottom of a parrot's cage, and I felt grubby beyond just the state of my clothes.

I needed a solid night's sleep to clear my head. My mother had always told me that things would look better in the morning. I doubted that would be the case in this situation, but at least I'd be better equipped to decide what to do about it.

I peeled the induction net off my skin and replaced it in its case. There was another thing. Here was probably one of the most valuable substances in the world right now. It didn't belong to me, and had only been lent to me for the purposes of an experiment, and I'd loaned a fair sized piece of it to a girl I'd met less than a day ago, ostensibly so she could use it as jewellery.

I couldn't believe how irresponsible I had been. I wasn't like this; it was almost as though someone was controlling me.

I found a sweatshirt draped over a nearby chair and pulled it on over the pink top. It'd need washing tonight anyway, and I couldn't be bothered to change just for the short trip home.

I locked up and headed for the exit, waving to the night guard as I left. My bike stood alone in the bike racks, which at least made it easy to find, and in no time I was cycling slowly through the deserted campus grounds towards my digs.

Back home I drank a full pint of water and brushed my teeth before stripping off my clothes and loading up the washer dryer. With that done, I'd reached the limits of my brain's ability to function, so I climbed into bed.

My mind drifted in a muggy haze. I could imagine that at least part of it was exhaustion, as I had put my brain under some considerable strain for several hours, but it felt like there was something else there too. Something I couldn't quite figure.

Still that was something a good night's sleep could fix. The brain is amazingly resilient, and does a great job of repairing itself during sleep. Whatever the cause of my fuzziness, I would almost certainly be in a better state in the morning.

For the second time that night, I quieted my mind and let the darkness wash over me.

-oOo-

When I awoke the following morning, I discovered that my mother had been right, a revelation that lasted for all of twelve seconds before I remembered what it was I had done.

I showered and made myself a mug of disgusting coffee, which I sat nursing until I could no longer hide from the day's responsibilities. I retrieved the pink top from the dryer and added it to my bag, then I wheeled my bike outside and cycled the short distance to the university and my dungeon lair.

The day passed without incident, although I found myself jumping half out of my skin at every slight noise that made its way to my ears. There was little enough to do with my equipment that I hadn't already done, so I forced myself to pay penance by writing up the events of the previous day.

I was brutal, putting down every fact I could recall. Should this end up going to trial for any reason, my notebooks would provide all the evidence the prosecution would need, but good science is built on absolute truth, regardless of how inconvenient.

I stayed in the lab all morning, and didn't even venture out for lunch. Again a penance of sorts. I was hungry, but I didn't believe I had any right to such luxuries as a full stomach and human company. So it wasn't until the end of the lunch break that I received the visit I'd been dreading all day.

A gentle knock sounded about ten minutes before the bell was due to ring for afternoon lectures. My heart leapt into my mouth and somehow managed to eradicate all traces of moisture. I tried to call out, but barely managed a squeak. The knock sounded a second time and, still unable to speak, I climbed to my feet and opened the door.

Mandy stood outside, looking nervous and uncertain. There was a red puffiness about her eyes that I doubt I would ordinarily have noticed.

"Are you alright?" I asked.

I'd given some considerable thought on how to handle this, our first encounter. I mean it should not have taken me three or four hours to write up my notes on the previous day's impromptu experiments, but I'd been continuously distracted by thoughts of Mandy, and what I should tell her.

The most sensible course of action, it seemed to me after all that thought, was to play it by ear. If she'd experienced the lapses as blackouts like she had the first time, then I could get away with feigned ignorance and genuine sympathy. I'd take back the induction net and reassure her as best I could. Things would go back to normal, she'd never need to know.

Again, I'm not proud of my thinking, but you could argue that I hadn't actually physically done anything to her that she hadn't planned to do herself, except maybe feed her a few calories with the hot chocolate and put her to bed without a bath.

I placed a concerned hand on her back, high enough to feel her bra strap underneath her top, which prompted a weird recollection from the previous day on how it felt to be the one wearing it.

She stepped into the room under my gentle pressure, then collapsed into a flood of tears as soon as the door was closed.

I pulled her into a gentle embrace and made shushing noises until she subsided.

"I don't know what's happening to me," she said through breathless sobs. "I... Something happened to me last night, and I don't know... I'm scared. I think I may be going crazy or something."

I settled her into a chair and crouched beside her.

"Do you want to tell me about it?" I asked, "I tell you what, I'll put the kettle on and make us a couple of drinks, and you start from the beginning."

I busied myself with the kettle while she gathered her thoughts.

"I guess it all started yesterday when I came down here. You remember I had that thing where I blanked out for a bit? That really weirded me out, I mean especially when I woke up leaning over you. I mean what would cause that, right?

"But then the same thing happened last night. I was with..." She blushed prettily. "I was with a guy, and we were in bed together, and things were getting kind of steamy, if you know what I mean?"

I nodded, encouraging her to continue.

"Well, that's when it happened. I blanked out for a few seconds. One moment he had his hand on my... You know?" She indicated her breast, and I could feel it all over again. "The next thing I know, I'm not wearing any knickers, and he has his hand between my legs.

"Before I can say or do anything, I blank out again, and the next thing I remember is waking up the next morning. I had this feeling like I'd had sex, but no memory of it. There was other weird stuff too. Apparently I changed the bed, and washed up, and cleaned my room, but I don't remember anything, and I'm really freaking out about it."

"You have no memories at all?" I asked, not wishing to seem too eager, but this was an important point.

"Well, there was this one thing, but it doesn't make any sense."

"Tell me anyway."

"My grandfather has one of those really old tellies, you know, with a kind of double aerial thing on top?"

"Yes..." I had no idea where she was going with this.

"Well it doesn't work now we're all digital, but I remember visiting him, and watching him fiddle with the aerial to get the best signal. It was always like kind of watching stuff through a snowstorm, you know what I mean?"

I nodded, and my heart sank. I could guess what was coming next.

"Well, it's the weirdest thing, but I kind of remember seeing the inside of a lab, a bit like this one, but all really fuzzy. I mean it was like I was sitting there doing nothing for ages, and nothing happened, like for ages." She emphasised the last word, drawing it out with her desperate frustration. "Professor, you've got to help me here. I'm going insane trying to figure out what's happening to me."

Inwardly, I breathed a sigh of relief. Not quite what I was expecting then, and I could work with this.

"So what did you do, you know while you were seeing this snowy image?"

"Nothing! I told you, nothing happened for ages. I couldn't move or anything. I was just really scared."

"Well, I'm no psychologist..."

"But you know a lot about brain stuff. I mean you must do with the work you do here."

"Well, yes I suppose so, but it is a wide and complex field. I could tell you a lot about the physical structure, but as to how it works in a finer sense... Look, can I ask if you've been under any stress recently?"

It was a bit of a no-brainer since pretty much the entire campus was preparing for exams. That had been another reason Janice had withdrawn.

"Well, I guess, kind of." She didn't sound convinced. "My course tests me on all kinds of stuff, and there's a sort of maths, literacy and IT thing coming up this week which I'm worried about."

"There you are then. Stress can manifest in a lot of ways, and I believe blackouts like this, whilst uncommon, can happen as a result of worry."

"So why the weird picture?"

"You really are asking the wrong person here, Mandy. This isn't my field of expertise, but maybe your mind took you to a safe place. Maybe you were back with your grandfather, maybe watching some old Frankenstein film or something."

"I guess, but how do I stop it from happening?"

"By not worrying. It'll probably never happen again in any case, but either way, once your exams are over, things should go back to normal by themselves."

"Well, okay, if you think so."

"I do. Now if we have that sorted out, I imagine you came to give me my, er, my necklace back?"

"Oh yeah. I'm still wearing it, kind of. It's so delicate, I didn't want to damage it."

She shrugged off her coat, and there it was in all its intricate splendour. She turned her back to me and lifted her hair out the way so I could peel it off.

"It felt kind of tingly in the shower this morning. I hope I didn't do anything to it."

"I'm sure it'll be fine."

So I would receive some small punishment after all. Still rebuilding and testing the intricate micro technology in this thing was preferable to facing the complex legal consequences of my actions.

I showed Mandy to the door.

"Thank you, professor." She landed a kiss on my cheek.

"What's that for?"

"For putting my mind at ease, and for letting me borrow that."

"No problem. Drop by any time, especially if you have any more blackouts. I mean I'm sure you won't, but just in case."

I closed the door and let out a long, deep sigh. Bullet dodged. And at least I had something to get on with this afternoon. The superconductor wouldn't have been damaged by exposure to water, so at least the most expensive, most important, most irreplaceable part of the net would be okay.

-oOo-

Stress related blackouts! Who did he think he was kidding?

In all fairness, if he'd suggested it to me yesterday, I might have accepted his explanation, but things had changed. Last night had been an eye-opener in more ways than one.

Well, I gave him the chance to come clean and he chose not to, so what he gets now is his own lookout. First things first though, let's get these exams out of the way.

-oOo-

It took a whole week to rebuild the induction net. As I'd expected, the superconductor was undamaged, but the electronics were fried. Still, there's a silvery lining to every cloud, and this, at least, gave me an opportunity to tweak the design.

I started off by adding a couple of limiters to control the feedback loop that had caused me to switch brains in the first place. The focus of my research was telepathy, not mind control, and like many scientists, I didn't want to give the military a reason to show any interest in my work.

It seemed sensible to include a switch on the limiters though. Without them, I had something that I knew worked, if in a different way than expected. The limiters might bugger things up completely, so it seemed prudent to give myself a way of undoing the changes if I needed to.

At least that's what I told myself. The incident with Mandy had been wrong, and I had no intention of repeating it, I said to myself, and ignored the little niggling part of me that wasn't quite convinced.

Next I tried to figure out a way of putting a remote trigger into the net so I could shut down the system from within my subject's mind. I gave up after about an hour of thinking. Any remote trigger I could imagine would be too complicated to implement.

Besides, I'd only need it if I ended up disabling the limiters in any case, and I had no intention of doing that, did I?

Lastly, once I'd tested the new design in a virtual setting, I sent it to the electronics department to etch, and gave them instructions to waterproof it all.

Micro-electronics isn't something you cobble together yourself from a few spare components and a reel of solder, but we were fortunate in having an electronics department which was leading the way in manufacturing customised micro-circuitry. Any circuit you could conceive, you simply put it together on their proprietary software, tested it on a virtual test bed, and dropped it into their manufacturing queue. Most days the complete circuit would be with you by the end of the day. If you need it protected against water or U.V. or similar, that was just an added coating or two sprayed on, and didn't increase the manufacturing time more than half an hour.

By rights, with most of the process being automated, the redesign shouldn't have taken more than a couple of days, but for some reason, I found myself struggling with some of the maths. I put it down to some sort of bug, after all, I had been feeling a bit thick headed recently. It was just one of the occupational hazards of working in education, and you got used to it.

Anyway, I had the changes completed, installed and tested by the time exam week finished. The next step would be to advertise for a new assistant/guinea pig.

Last time I'd simply typed up a description outlining the sort of person I was looking for, and printed out enough copies to put up on all the various bulletin boards. I pulled up my saved copy of the flyer, and decided it wasn't particularly eye-catching, so I grabbed a few pieces of paper from the printer and started doodling.

I'd never been that great at art as a child, but half an hour later I had cartoon people, wearing girly tops and fancy necklaces, zapping thoughts to each other, underneath a hand drawn title that read, 'Ever wondered if telepathy was possible?'

It would definitely stand out. I measured up the blank space, and altered my existing flyer so the relevant information wouldn't overwrite any of my doodles. One test print to make sure, then I put my decorated sheet into the printer tray and added the words.

The final product looked pretty good, so I photocopied a stack, and set about distributing them about campus.

By the end of the day, I had volunteers queuing up outside my door. Way more than last time, so it seemed it did pay to put some effort into your advertising.

As before, most of the lads were put off by the requirement to wear a scoop-neck top and pretty necklace, but I had a few who didn't seem fazed by the thought. I also had a larger selection of girls than last time. Janice popped in to wish me luck, but she wasn't interested in trying again. By the time I'd been at it for a couple of hours, I had a number of possibles short-listed.

Then Mandy walked in.

That was the moment I realised, I'd been waiting and hoping she'd turn up.

"How have you been?" I asked.

She laughed. "You make it sound like we're old friends meeting for the first time in forever."

"Well, after our last encounter, I've been worried."

"Well, you can put your mind at ease. I did some yoga and tried to relax, and I've not had any more blackouts. In fact I did really well in my exams, way better than expected, so thanks for your advice."

"Well, I'm glad. Are you just here to say hi, or are you thinking of signing up?"

"Well, if truth be told, I could use the money, and I really did like wearing that necklace thing."

"I'll put you on the short-list," I said, writing her name under the half dozen or so I had already.

Mandy Burrows. Contact email and mobile number. All sorted.

I interviewed for another half hour and short-listed a couple more. By then the crowd had thinned considerably, and I'd lost enthusiasm for the task. There was no doubt in my mind who I'd be choosing.

-oOo-

She started the next day. One of the great things about art students was that they had very few lectures and a lot of freedom in choosing when to work on their projects. Mandy was happy to bring her portfolio with her and work on it between experiments.

With the limiters in place, the induction nets worked very differently, which is to say they practically didn't work at all.

The next few days were progressively more frustrating as I'd set up one experiment after another, with Mandy in one room turning over picture cards, and me in another room trying to sense what she was seeing.

From the outset, it was a bust. I could have done better simply guessing the answers. Between experiments, I'd tweak levels on the two induction nets and we'd try again. By the end of the third day, I was so angry I was ready to scream. I picked up the nearest thing to me, which happened to be a half drunk mug of cold coffee, and was about to throw it across the room when...

"Hey, it's alright, don't be upset."

Mandy was totally isolated in the test room, and there was no way she could see me.

"What?"

"I can feel how angry you are." The door opened and she stepped into the main lab. "It's okay, things will work out."

"You could feel that?"

"Yeah. Every time we start a new experiment, it's like I have this frustration building at the back of my mind. I know it's not me because I'm totally calm as soon as you turn everything off."

"Why didn't you say anything?"

"I thought we were trying to make the cards work."

"Well yes, but we're investigating if we can send feelings as well as thoughts. Remember I said telepathy and telempathy?"

"Oh, I'm sorry. I guess I messed up."

"No, no you didn't. Look, this is a good thing. It means something's working at least."

"You don't look too happy."

"No, I am. It's just that I expected a bit more."

"Why? I mean surely anything's good at this stage."

"Yes, except it's actually worked better than this before now."

"So what changed?"

"What?"

"Something my dad always says. If it worked and now it doesn't, you must have changed something. What did you change?"

"Well, I guess there was one thing..."

"So change it back."

"Is not as simple as that."

"Why not."

"There were... other effects. I wasn't too happy about them. Look I'm going to have to think about this. Can we pick up again, say tomorrow afternoon?"

"Sure. I'll see you tomorrow after lunch."

She turned her back on me so I could unclasp the net, then she was gone like the sunshine when the rain comes.

She was right. This whole thing had worked better without the limiters, and if I wanted to make it work again, I'd have to disable them. Only then there was the whole issue of switching minds, which meant I'd have to come clean about what had happened before.

Still there really was no helping it. I placed Mandy's net on the workbench and teased open the casing. It would only take a moment to switch off the limiters. What would take time would be figuring out how I would tell her about last time.

-oOo-

He was so easy to manipulate.

I don't know, there seems to be a naiveté amongst older men in regard to pretty girls. It's like they don't think we're capable of dishonesty or something. Maybe just wishful thinking on his part, but I've found it useful these past few days.

First with the cards. I've had no trouble cheating at the experiments we've been doing. In a way, it's a shame to lead him down the garden path, since his experiment really does work, but after he altered the electronics on my necklace, nothing's worked quite the way I want it to. So what choice did I have? I had to do something to persuade him to revert to the old set-up.

Being able to sense how he felt through the link was invaluable; it allowed me to gauge exactly how far to take things before intervening. I don't know why he wasn't able to sense emotions from me in the same way though. From what I understand of it, the link was supposed to be something of a two-way street, with him getting the lion's share of the information. Perhaps the limiters were interfering with his capacity to sense more than mine, or perhaps it has something to do with the trading of mental ability, which is something else he hasn't noticed.

Still, whatever the reason, I have him where I want him. I just need to think about how to handle tomorrow. It shouldn't be too difficult though. Like I said, he is so easy.

-oOo-

"Mandy? I said not to come in till this afternoon."

"Did you, professor? I'm sorry, but I saw you working on the necklace as I was leaving, and I figured you'd have it sorted by now. I'm sorry, but I just couldn't wait. Can't we just try it?"

"Well I suppose, but I have to tell you something first."

"No time. I have a lecture in half an hour." She ran into the test room and closed the door.

Well, I could always set the current on absolute minimum. Without the limiters, it would build over time, but it would hopefully pass through an intermediate phase before we switched bodies. With luck, we wouldn't even get to that point in the time we had available to us. That way I'd have a chance to explain before things went off the rails again.

"You ready?' I called.

"Yeah, go ahead."

I took a deep breath and threw the switch.

Something was horribly wrong. The current was at its maximum, not its minimum. With the feedback multiplying it each passing second, it felt like my brain was being squeezed by a giant vice. It only lasted a few moments though, before the circuitry burned out. But what the hell had caused that?

I opened my eyes and found Mandy's face staring at me out of the mirror. A wisp of blue smoke emerged from the small enclosure that had formerly held the induction net's electronics.

"What the hell?"

The door opened and my body stepped through. I didn't much like the way it was smiling.

"Hello, professor. How do you like your new body?"

"Mandy, what the hell?"

"You already said that professor. Actually, I really ought to start calling you Mandy, since you're going to be stuck like this from now on."

"I don't understand."

"That doesn't surprise me, if what's been happening to you is the converse of my own experience."

"What?"

"I should confess, professor. You see I haven't been entirely honest with you. Not that you've been the personification of that particular virtue yourself."

I really was struggling to follow, and what made it all the stranger was that I knew that I shouldn't have been.

"You remember the first time you tried this contraption with me, professor? Remember, the day we first met?"

I managed a blank stare.

"Well, at least you have the decency not to deny it. The first time you used this thing with me, I lost a few seconds. I'll admit, I didn't know what caused it at the time. I just remember there being this disjointed shift from me admiring what I thought was a piece of jewellery in a mirror, to me leaning over you, turning a dial.

"I've read your journal entry for that event, professor, and I can understand why you tried it. You'd had a long run of failure, and just wanted to see if it might work with me. You didn't expect it to work at all, let alone to give you results it did. It was excusable, and no harm done.

"Professor, if only you'd stopped there. But you didn't, did you?"

"I..."

"No. The second time was premeditated, and done without my permission. You know this to be the case, and you knew it was wrong even as you did it. How did you describe it in your journal? 'Tantamount to rape' were your words, I think."

"How do you..."

"Know what you wrote in your journal? Well, you were kind enough to give me a key to the lab a few days ago, weren't you? And it's not that hard to figure out someone's password when you can see into their mind."

"I don't..."

"You don't understand, which is excusable since I haven't told you the bit you don't know yet. You see, the second time you used the machine, I didn't black out the way I did the first time. One second I was having a bit of fun with Steve Jensen, the next, I was sitting in your lab, seeing the world through a blizzard of interference, just like I described last week. I couldn't move at first, but then I was back in my body again, and Steve was getting really busy. Once again, that lasted for only a few seconds, and I was back here again.

"That time I was stuck in your body for hours, sitting in that chair, slowly freezing my – or rather your – arse off. I still couldn't move, but by degrees I realised I was seeing and thinking more clearly. I wanted to know what was happening, and your brain furnished me with the details. I found I knew and understood what your great invention was, and how you were using it at that moment in time. I even felt something of your inner conflict, and that mitigated some of what you'd done, but you still went ahead and did it anyway."

"Look, Mandy, I know I crossed a line. What I did was uncon..., uncon..., unconsc..."

"The word you're looking for is unconscionable. Last week I wouldn't have been able to tell you what it meant, now I do, and a lot more besides. Now it's you who's struggling.

"I had quite a few hours to get used to things that time. While you were busy enjoying Steve's attention, I was stuck in a body I couldn't move, in an empty room that was cold and getting colder. I learned quite a lot about your experiment, and astonishingly, I found I understood it too.

"The nearest I can figure out is that while we've been inhabiting each others bodies, we've been adapting to each others brains as well. I'm guessing you've been feeling a little sluggish these past few days."

"Well, er..."

"You don't have to say anything. I've noticed you losing your edge. I mean I wouldn't have been able to fool you as easily the day I first met you."

"Fooled me?"

"Yes, but I'm getting ahead of myself. You know, the effects seemed to last for a while after we changed back. When I woke up the following day, I felt sharper than I've ever felt in my life. I knew that I'd had sex the previous evening, or rather you had in my body, and I decided to test you to see how honest you'd be with me.

"I pretended ignorance about the events of the previous night, and you responded by giving me that shit about stress blackouts. That's when I decided I'd have some payback once I'd finished my exams.

"I'd been dreading those exams you know? They were on all the things I'm no good at, like maths and English comprehension, only when I sat down in the exam hall, suddenly they were easy.

"It had to be the few hours I'd spent in your brain. Somehow that time of added clarity stayed with me, at least in part. That was when I decided what my payback was going to be. In exchange for what you'd taken from my body, I was going to take some of your mind."

"That's not possible."

"Professor, you of all people should realise it is. I know what you intended to achieve with this machine of yours, but you must appreciate what it's capable of. I mean I had to figure out a few additional things in order to make the transfer permanent. And then, in order to take advantage of that new knowledge, I had to work my way back into your research.

"Still, that was pretty much assured the moment you advertised for a new assistant. I knew that if I turned up, you'd pick me.

"But then you made some changes to your machine so it didn't work like it had before. I could feel myself picking up a little bit of your brain power, but nothing like I did that night when you invaded my mind. I needed you to change it back to the original set-up., so I started cheating with the cards."

"Cheating?"

"Yes. Whatever I turned up, I'd think about a different pattern. The machine worked, professor. Everything you wrote down matched the patterns I thought of. It's not your fault that I was giving you false responses. I was manipulating you, making you so frustrated, it was easy for me to persuade you to change things back the way they had been."

"But I set the current at absolute minimum. I don't understand why it overloaded the way it did."

"Because I sabotaged it, professor; it really didn't take much doing. Open the control panel, clip a fly lead across the current control, close everything up again.

"You may not have been getting much out of the last few days' experiments, but I have. I've been able to sense your feelings and thoughts, and I've picked up a fair amount of your intelligence as well. I've also been coming back here after you went home. The guards knew I was working with you, so it was easy to persuade them to let me back in. I read all your notes, including your journals, and I did a lot of thinking about what would happen if that positive feedback were allowed to run all the way out of control.

"With the feedback running at maximum, the effect would build rapidly over a few seconds until the circuitry burnt out. The intensity of the signal would ensure our minds were imprinted more or less indelibly onto each other's brains, even after just a few seconds, and the abrupt cut off would make the chances of our flipping back almost impossible.

"So you see, professor, you wanted to be me so much, and now you get to be me for the rest of your life. Of course, it means you'll have to get by with my mediocre intelligence, but then there has to be some price to pay."

"But why would you want to be me? I'm twenty years older than you, and definitely not so attractive; it doesn't feel like a fair trade."

"Oh, it isn't, professor. You see, I get your remarkable brain and your amazing machine, and they are worth so much more than my youth and beauty. Once I've fixed the induction net, and all that will take it's a repeat request to the electronics lab for a new circuit board, I can hunt around for someone I'd really like to be, and repeat this whole process with them."

"You'd just take someone else's life? After all, you've said about how much of a violation my own actions were, you'd go right ahead and do worse?"

"But that's the thing professor. It was your own invasion of my mind that decided me on this course of action. You've shown me that there's no such thing as live and let live in a dog eat dog world.

"I remember this line from a film I saw a while back. 'Do unto others before they do unto you.' I thought it was kind of sick then, but now I can see how true it is. If you just sit back and assume everyone you meet is going to be nice to you, sooner or later you're going to come across some rat bastard who'll take advantage of you. So why not be the rat bastard first, eh professor? Why not take your opportunities when they come?"

"I don't think it'll work the way you want it to. It didn't work at all with my last lab assistant."

"Yeah, I read about your lack of success with her, and I went to meet her. She just had an over-active mind. Always ticking over, even when she's asleep. Most people are a lot more laid back."

"So who did you have in mind to switch with?"

"I don't know, I kind of like the idea of being a man. Better plumbing and no annoying leakage every month for one thing. No glass ceiling, more control over my own destiny. I was actually thinking about Steve Jensen. You know he's kind of good-looking, he's pretty intelligent – I mean not genius smart like you, professor, but I'd be happy with a little less - and he comes from a wealthy family."

"I thought he was your boyfriend."

"So did I, but he hasn't called since he fucked your brains out that evening you climbed into my head, so he's kind of got some payback coming himself."

"But then he'll figure out what the machine does and he'll steal someone else's life, and the whole cycle will keep on repeating..."

"I guess. Unless I destroy your contraption after I've switched with him."

"Or unless I do now," I muttered.

"What did you say?"

"This thing is too dangerous. If this got into the hands of the government, or even someone with real ambition, the world would go to hell."

"You can't uncreate something professor. Whatever's made can't be unmade. If you can conceive a machine like this, so can someone else."

"Yeah, but they'll only be able to build it if they have this stuff." I peeled the induction net off my neck and held it up. "You know I said it was really delicate?"

I closed my fingers around the intricate latticework and squeezed. I was hammering nails into my own coffin, but she had to be stopped. No one else could know what this machine could do. My mind was filling with horrifying scenarios, one after the other:

Spy networks infiltrating other countries by replacing their leaders with their own operatives. Powerful people being taken over by avaricious and unscrupulous individuals. Eventual chaos as knowledge of the device became more generally known, and people found it impossible to trust that anyone they knew was the same person today as they were yesterday. So many more worse things as well.

I opened my hand and dropped the mangled remains of the net on the floor.

"Nice try professor, but if you shaped this stuff once, I should be able to do it again. It'll just take a little longer is all. Now, I'm going to have to ask you to leave, and not come back. I won't be too mean to you, just say you damaged some delicate and expensive equipment, for which you've conveniently provided me with the evidence. You won't get near this lab again, you know?"

She was right, so I had to make sure she couldn't either. I grabbed the front of my top and yanked at it with all my strength. Fortunately, it was made from some delicate fabric which I could rip readily enough, even with my own feeble strength. This would have to be convincing, so I stepped out into the main lab and ran as fast as I could into the nearest wall, smashing into it hard enough to make my head reel.

"What the hell are you doing?" she asked.

In response, I threw myself against another wall and screamed. It hurt like hell, so the scream was easy enough to generate.

"What? No, stop it." She advanced on me, grabbing me by one wrist and clamping her other hand over my mouth.

I bit down on it and was rewarded by her yelp of pain and the hand withdrawn. I screamed again as loud as I could. My lab was in a really remote part of the science building, but I was sure someone would hear me.

She hit me. What would have been no more than a stinging slap if she'd been in her own body, was hard enough to loosen some of my teeth.

"No, please," I screamed. "Please help me, someone."

"Shut up," he hissed. "You think you'll get away with this? It'll be my word against yours, and I have your reputation of respectability you know."

I did know, which meant I had to make this really convincing. I screamed again, and this time, I could hear footsteps at the end of the corridor.

She could too, and she knew how compromising this looked, so she let go my wrist.
I ran and threw myself against the main computer console. The sharp switches snagged my clothing and bit into my skin, and the machine itself made a distinctly unpleasant sparking noise. I heaved at the rack with all my meagre weight and strength and managed to topple it.

"Stop it," she yelled, sounding really angry.

"No, please," I said in return, sounding really pathetic. The footsteps were near enough that their owners should be able to hear even my quiet protestations now, and the emotions in this young body were so much closer to the surface. It really didn't take much to make this convincing.

The door opened and a couple of my recent students stormed into the room.

"Professor?" One of them asked, looking worried and uncertain.

"She went mad," Mandy said, pointing at me.

"Liar," I screamed back, my voice distorting with raw emotion. "He tried to force himself on me."

"What? No! It was her. She just went nuts. Started tearing the place apart."

"Liar," I screamed again. "Would I do this to myself?" I held up the torn remains of my top.

"She's lying," Mandy said, trying to sound reasonable. "You know me guys. I'd never do anything like this."

"I'm sorry, professor," the first one to arrive said. "I don't know what went on here, but we'd best all just sit tight until someone comes along who can figure it all out. I'm going to call security, is that okay?"

"Yeah fine," Mandy said, looking pissed. "I was going to do that anyway, to have this hysterical young lady removed from my lab before she does any more damage."

The spokesman of the new arrivals – Liam I think his name was – picked up the phone while his friends positioned themselves between Mandy and me.

Do any more damage? There was one bit of damage I still needed to do. I had some pretty hefty magnets lying around the lab from some of my earlier experiments. Of less use was that they were all large and heavy, and a long way from the hard drives I wanted to scramble.

I backed up into the corner of the room where I had them stored, and settled down to await my opportunity.

It came with the arrival of the security detail. Everyone turned as the door opened, and I took my chance and picked up the biggest magnet I thought I could manage. Keeping it behind my back, I stepped forward towards the remains of my mainframe, and sat on it, sticking the magnet close to the drive bays.

The security guards started by talking to Mandy, which I suppose was normal, given this was his lab. He told them a version of events that involved me becoming hysterical when his experiment actually worked.

I interrupted by calling him a liar, and accusing him of luring me down here on a pretext.

I was told to be quiet, that I would be given my chance to have my say. They pointed at the chair next to the desk where I kept my PC.

It was too easy. I peeled the magnet off the mainframe drive bays and took it with me, sticking it near to where the hard drive should be on the desktop.

The screen flickered once and froze. About ten seconds later, the blue screen of death appeared.

"Professor?" I asked.

"Miss Burrows, you'll get your turn," the security guard said again.

"Yeah, it's just... I think there's something wrong with this computer."

I backed away from it, taking the magnet with me.

"What!" Mandy yelled, running towards the seat I'd just vacated. "What did you do to it?"

"Nothing," I replied. "What do I know about computers?'

She turned on me and advanced with thunderclouds boiling behind her eyes.

I backed up to the shelf with all the magnets and replaced my instrument of digital destruction alongside its companions.

"I didn't do anything. Guys, he's gone nuts."

"Professor, please back away." The security guard reached for his Taser, and Mandy realised she had no option.

-oOo-

What followed was more or less as inevitable as it was unpleasant. After Mandy had accused me of freaking out and wrecking the place, I countered with a story of a sad, lonely man indulging in weird, erotic fantasies. Witness the number of times he'd been seen wandering around the university grounds recently wearing women's clothing and jewellery; witness the fact that he was doing just that when I'd called for help.

I talked about the earlier failure of his experiments, and gave them Janice's name. I told them how I figured he must have gone over the edge, and how his 'experiments' in telepathy had somehow turned into nothing more than some bizarre foreplay to an exotic, erotic scenario.

In short he was nuttier than squirrel shit, and he'd tried to include me in his sexual fantasy. Maybe he had come up with some theory as to how telepathy could be achieved, but it hadn't worked, and he'd lost it.

He didn't stand a chance. When it came to his word against mine, the authorities were far more inclined to believe the pretty girl with the bruises and the torn clothes, especially when some of the bruises matched the professor's hands.

He ended up in prison, and I have to admit I felt bad about that. I tried to visit him, but he declined to see me. I've often wondered how such a sweet girl could turn into the sort of monster he ended up being. Maybe it was latent in me all along, and it infected her the moment she woke up in my brain. Maybe there's something in the old adage about power corrupting. I no longer have the capacity to come up with answers to those sorts of questions.

As for the rest, the small amount of room temperature superconductor was returned to its inventor, and who knows what he did with it, the wrecked computers were scrapped, and world disaster was averted.

What about me? I had a bit of catching up to do to learn everything Mandy already knew about make-up and beauty treatments and the like, but I still had enough residual intelligence that I managed it easily enough. I graduated with honours, and I now own my own boutique, which is doing pretty well.

You know, I started out in science because I wanted to make the world a better place, but I've realised you can do that just by helping to make it more beautiful.

I find I really like being a woman. Sure, what Mandy said about inadequate plumbing, monthly unpleasantness, chauvinistic attitudes and the rest are a real drag, but the community of women more than makes up for that. I haven't felt lonely since becoming Mandy.

Yeah, part of that is because I'm pretty enough that I get a lot of attention from the guys, but then most of them end up being a real disappointment when it turns out all they want is to get you into bed, then go away.

Mainly it's because women – most of them at least – are so amazingly supportive of each other, and life is so much better when you feel loved and appreciated.

If I still had the genius brain, I'd probably be looking at ways to make everyone think and act more like women.

Probably as well I'm not much of a thinker any more, eh?