Many moons ago I wrote "Ka = d(Ka.nT)" for the Deansgate SF Portfolio. For ages (and I mean the best part of a year) I never heard anything, and assumed it had been rejected, shredded, and recycled into an Oxfam writing pad. One day, however, I received an email which basically said it had fallen down the back of the sofa, and would I still like it appraised.

To cut an increasingly long story short, it was rejected. The main reason was its length (I had an early copy of the writers' guidelines which specified 8,000- 10,000 words; it had later been revised to a lower limit of 2,000!). It was suggested that I should submit other stuff, as my writing was quite promising.

Unfortunately I didn't have any suitable short stories to submit, so I decided to write one. Even more unfortunately, it seems to have overrun on length, so probably won't do for the portfolio. I might trim it down and submit it; I might let it slide and write something else. Whichever I do, below is the original, full length version.

It was the pain that was worst, though. The pain of skin being pulled and stretched. The pain of bones growing in thickness as every plane of molecules raced away from its neighbours, like ranks of soldiers dashing line-by-line towards an invisible enemy. The pain alone would be nearly enough to kill him.

But he wouldn't know that. He wouldn't see the distortion of his body. He wouldn't feel the pain. Not for another hundred-thousand-millionth of a second, or thereabouts. Not for another lifetime.

An instant later the process was reversed. His whole body was decelerated at such a rate that, under normal circumstances, he would have been killed outright. But these were not normal circumstances, and this was not a normal deceleration in the conventionally understood meaning of the word.

But conventional deceleration was to follow. The initial jolt which retarded him so immediately had now passed, and his body continued in free flight towards a hundred yards of expanded foam blocks. Fortunately, they had been specifically selected and graded for just such an impact, and he barely felt a thing as he hit the first of them; a low density grade, barely solid enough to hold its own weight. They didn't last long, but instead passed him gently onto the next block, then the next, then the next.

With each group of blocks, the density of the foam increased, and its retardative ability did likewise. After ninety yards the individual vesicles were mere millimetres in diameter, and his speed had been slowed to that of a fast run. Unfortunately, he was also fast running out of foam.

He exited the decelerant into a clumsy stumble, quickly found his feet, then slowed to zero as his head became intimate with the big steel doors of the aircraft hangar. Although he was moving slowly enough for the impact to generate nothing more than the sound of some ungodly theatrical thunder, he nevertheless took the opportunity to collapse to the ground.

Finally his nerves caught up with him, and the last of the pain that had been generated over a mile away subsided. His screams had been lost in the depths of the foam.

Like a frightened animal his head darted left and right, trying to make some sense of the unfamiliar sights and sounds: trying to comprehend the very nature of his environment. Everything had width and height. Colours were largely stationary. And his body could touch, feel, and impact with things. This was too strange. Too, too strange.

He pawed the ground, expecting it to absorb his hand as it should do. On discovering that it didn't, he began to feel everything: the doors, the fragments of foam that stuck to him, his own body. He looked back down the tunnel of mutilated foam towards the source of his re-creation. The huge, copper wound circles. The banks of computer screens.

There were his answers. He knew inside that he had something to do with them. If only he could get a closer look. Yet no matter how much he concentrated, no matter how much he imagined himself being a hundred yards further along the hangar, he singularly failed to appear there. In his mind he damned the physics of this vile nightmare.

In desperate frustration he threw his arms wildly around, successfully bloodying his nose, and bruising his cheek before his mind began to regain memories of bodily control. He lay his hands on the floor, and once again mentally noted how solid it felt. He began to wonder if perhaps, just perhaps, he might have to use this solidity to manoeuvre himself into the relevant location.

It took a little experimentation: pressing down with his hands, pushing up with his body. Pressing down with sufficient force to move his torso. Leaning forwards and curling his legs below him until he was kneeling.

Slowly the memories began to return. Images of running, dancing and, of course, walking began to filter through the brainwash of colour that had become so commonplace. He remembered people walking. He remembered doing so himself. His body still had the muscle and sinew to perform the task - it was just his mind that was lacking.

As experimentally as a lamb taking its first steps, he rose to his feet. As clumsily too. At first he fell, but balance soon returned as his brain remembered how to interpret the signals from his inner ear. Step followed faltering step, his hands forming the third supportive leg of a human tripod as they pressed firmly against the cold steel of the hangar walls.

The process of tapping into unused memories seemed to open the floodgates to a cascade of thoughts, images, and abilities. Within minutes he was walking again. Unsteadily, maybe, but not bad after a forty-three year break.

He flopped into a chair in front of the computer terminal. Although his body didn't ache as such, his mind was so uncomfortable in these whole surroundings that he felt as though he should be exhausted. The flashing block of green that made up the cursor was the closest he'd come to an understandable environment since he'd arrived here. No, since he'd returned here.

The area was lit with a single desk lamp. All other light came either from the flashing indicators that filled three racks of equipment, or from the perspex "windows" set high in the walls of the hangar. They belied the age of the place even more than the rust eaten panels of corrugated steel, being yellowed by sunlight, and greened with moss and mould. The whole place was, quite simply, dingy.

But his eyes were fixed on the cathode ray tube in front of him. His brain tried to make sense of the jumbled mess of pixels that he knew represented letters and words. One by one he picked out groups of dots, examined them closely until his mind remembered their meaning, then moved on to the next. Letter by letter he read, sounding more like a five year old novice than a thirty-two year old lecturer. He matched unfamiliar shapes to their equivalents on the keyboard, finding that the better formed letters thereon jolted his memory even more. Letters turned into pairs, long forgotten rules of grammar returned to correct his pronunciation. S. H. S. H. S. H. Shhhhh.

Phonetically he built up word after word, inserting prepositions that had been omitted by the programmer in order to construct whole sentences. His command of English was returning. And with it, his understanding of the program.

His index fingers stabbed down onto the keys, ultimately being joined by his remaining digits as he remembered he could touch-type. Obscure commands leapt from the recesses of his mind and instinctively fell into patterns with his fingers. The words were gobbledygook, filled with command line switches – hyphens, asterisks and single letters – which all contrived to drive the machine under his full control. As messages appeared on the screen, he couldn't help but mumble them under his breath, articulating his lips only slightly. But more and more of them began to awake the speech centre of his brain, and soon he was talking again. Not just reading the messages, but actually talking to the machine.

Yet all the while – despite revelations about his abilities that should have had him whooping with joy – he never once smiled.

Eventually he hammered the last of the commands into the computer. Its response was as expected. He fell forwards onto his arms, and cried.

A winking LED told him that the video camera was recording. As he returned to his seat, the magnetic tape stored an image of some odd breed of martial arts expert, curiously bowed and never once breaking eye contact with the lens. Perhaps it was a subconscious by-product of the old theatrical adage, "never turn your back on an audience". Perhaps not. Either way, he waddled awkwardly backwards towards his chair, before letting his weight fall clumsily into it, directed into the right position by its arms. His elbows fell naturally onto his knees, his hands were clasped, and he rested his chin onto the knot of fingers. He took a dramatically resigned deep breath – the sort that lifts your shoulders and stretches your body to one step short of yawning. Then, after an audibly nasal exhalation, he spoke.

"Where to begin? Where to begin? It's hard to know what to say, Frank. Perhaps I should keep this technical to avoid boring you shitless, but I know you'll have to show this to the police – and I'm sure you could well do without having to spend hours explaining my every word. God, this is going to cause you enough hassle as it is – and I'm sorry for that, really I am. Bollocks. I guess I'll keep it simple, Frank. That's what they say, don't they? 'Keep it simple, stupid.' Sorry if it bores you, but you'll soon understand why. If you don't already know."

He rested his forehead against the knot, looking between his legs at the dusty concrete floor, breathing deeply. He stayed there for a full five seconds, making sure he had clearly drawn a line between his introduction, and what he was about to say. During that time he pondered his opening sentence, but couldn't find one that worked. Eventually he raised his head and propped his chin once more, looking into the camera and imagining a virgin group of first year students. That, he decided, was the best way to pitch his words at the right level. He remembered being a lecturer once, but that was a long, long time ago. That was yesterday.

"Okay then Inspector, or Chief Inspector, or whoever you are. Here's a beginners' guide to tachyons. I'm afraid that you'll have to take much of what I say on trust – any particle physicist will be able to confirm it, but I think the maths might be a bit too much if I tried to prove it to you.

"Right, let's start with Einstein. In his theory of relativity he states that the speed of light is a constant. This is one of those 'trust me' bits, because common sense has a real problem with it. To give you the best known analogy, suppose you're on a train travelling at ten miles an hour, and you throw a ball in the direction of travel, again at ten miles an hour. Obviously, relative to the earth, the ball is travelling at twenty miles an hour.

"Now, if you shovel a bit more coal into the furnace, and crank the steam pressure up full, we can suppose that you might be able to travel at, say, half the speed of light. Now imagine you turn on a torch. Obviously the beam from that will be travelling at the speed of light – which we call 'c' for convenience. Now common sense says that relative to the earth, the beam of light must be travelling at 1.5c – i.e. c from the torch plus a half c from the train. What Einstein said, and what's been proven since, is that the beam still only travels at a speed of c.

"The point is that c is a fundamental figure in the universe. No matter what you do, light cannot travel any faster or slower than c. The packets of energy that make up a beam of light are created already moving at that speed; they can't go any faster, and they can't go any slower. You with me so far?

"Anyway, Einstein's equations showed that as things approach the speed of light, they get smaller and heavier. Just trust me on that one. What follows is that objects travelling at the speed of light have no length – which means they don't exist – yet they have infinite mass. Basically the whole of space and time goes a bit screwy, so most people thought that the speed of light was an upper limit – that nothing could ever travel faster than c.

"Trouble was that it would be really nice to have particles that could travel faster than c. They help to simplify quite a few equations. In fact, they seem to slot in so well with some of our models of the way the universe works, that it's hard to believe they don't exist. A reappraisal of Einstein's work also actually supports the theory – it just says that nothing can travel at the speed of light, but doesn't actually preclude anything travelling faster. Consequently, a growing number of physicists actually believe that these faster than light particles exist. They call them 'tachyons.'

"Now the important thing to remember about tachyons, is that they can only exist above the speed of light. When they are created, they're already travelling faster than c, and if they slow down to the speed of light, they simply cease to exist. Perhaps that's why so many physicists believe in them – there's no way to measure them, or to test for their existence without making them vanish, so it's quite safe to believe in them, knowing that you can never be disproved. By the same argument, of course, you can never be proved right. Well… not until now, at least.

"You see, I've made the study of tachyons my life's work. My doctoral thesis was on a reassessment of some of the work done after Einstein, but based on the premise that the speed of light is a lower, rather than an upper limit. In this way I've managed to shed some light onto the world of the tachyon; and it's an odd place, believe me. Mathematically speaking, we live in a world with three dimensions of space – up/down, left/right and forward/backwards – and one of time. Tachyons, on the other hand, exists in a universe with one dimension of space, and three of time – but I'll come on to that in a little while.

"Anyway, my theoretical work led me to believe that it might be possible to spontaneously accelerate an object to superphotonic speeds – to faster than the speed of light. So I came back here, to my old alma mater, to begin a series of practical experiments. The university bought this old airfield back in the sixties; they'd planned to build a huge radio telescope on it. Unfortunately cutbacks soon stopped that idea, but their loss was my gain – two hangars, pointing directly at one another, with a mile long runway in between. What more could I have asked for?"

He leaned forwards until his whole weight was on his legs, then rocked himself to standing. A couple of steps brought him close enough to press the 'stop' button on the camera; the LED extinguished itself. He was tired. So very, very, tired. He was still a little unsteady on his feet, and walked like an old man towards the piles of expanded foam. He picked a part whose density would at least hold his weight, then collapsed onto it.

When he awoke there was no green-stained glow from the mould spattered perspex windows. It was dark outside, and what little light they had provided was now just a fragment of his memory. Now the only light in the hangar came from the flickering screensavers on half a dozen monitors, and the sherbet pip pinpoints of thousands of LEDs. He made his way unsteadily to a large circuit breaker, and braced his hands against it. He pushed up hard with his thighs, transferring the movement through his stiffened back into the red and yellow handle of the device. A hefty clunk bathed the hangar in the flickering sodium glow of cheap, old strip lights. Half of them failed to work at all. Three more danced a quickstep of orange expulsions as they repeatedly tried, but failed, to fire. The rest illuminated the hangar in such monochrome ferocity that it seemed as though everything was being viewed through a sniper's night sight.

He looked up at the three flashing lights. He wondered what they were trying to say. Why didn't they change colour? Didn't they realise that their words made no sense? Then he remembered where he was, remembered what they were; and stopped trying to make sense of anything anymore.

He made his way to the video camera, teetering with every step. It was already hooked up to a television, so he switched on the set, rewound the tape, and reviewed what he had recorded previously. He felt an urge to re-record it all, but he knew it would be a fruitless pursuit. He could record it a thousand times, and it wouldn't sound any better. There was no good way to say what he wanted to. He decided to continue with it as it was.

"Sorry about the edit there – I needed to take a break. I hadn't slept in over forty-three years you know. Or maybe just the same, but in minutes.

Anyway, on with the story of my experiment. I did it, you know. I did it. A mile away from here, in a similar hangar, there's the world's first COMAG resonator. COMAG stands for… stands for… something… confined something. I don't know right now, words are still very difficult for me. Confined magnetism. That's it. The world's first confined magnetism resonator.

"Basically, it's like a magnetic version of a laser. By confining a changing magnetic flux as a standing wave, I've been able to add high level impulses in order to shape and increase the overall magnetic level. It takes a while to build up properly, but what I've created is basically a huge electromagnet, far beyond the limits of anything else available, yet which doesn't need enormous amounts of short term power."

His face fell into an emotionless façade for a few moments as he gathered his thoughts. He was trying to construct a sentence in his head – one that would simply and clearly explain away a decade of physical research. He stumbled clumsily over the first few words before deciding that such details were unnecessary. His laboratory notes were comprehensive enough for any reasonable scientist to follow, and the video had to be kept simple enough for the police to understand. He wrung his fists into another knot, and mimicked them with a similarly contorted frown. Eventually he spoke again.

"You don't need to know the details though, do you. It's all here if you want anything confirmed, but right now you just want to know what I did, and why.

"Well, in case you hadn't guessed, I managed to accelerate a few things to superphotonic speeds – greater than the speed of light. At first I couldn't be certain that my results were correct, because once you accelerate things to that speed, they effectively cease to exist in our own world. There was no way to confirm what I'd done – I might have just found a super-efficient way of vaporizing things for all I knew.

"That was when I built the decelerator. I figured that if I could decelerate something after I'd accelerated it, at least I could be certain that it still existed. That's what this lot is – a highly confined magnetic decelerator, positioned as the target for the accelerator.

"It took a while to get the timings right, of course: I have to start the deceleration process before I've even fired up the accelerator, because the two are synchronized by sub-light speed electronics. Nevertheless eventually, some three months ago now, I managed to accelerate and decelerate an object successfully.

"The first thing was an apple. It came out okay – even tasted fine – so I moved up in scale and complexity. After melons and grapefruit, I moved onto a radio receiver. I put it in whilst it was turned on, and it was still working when it reached the other end – or at least it was still working until it came flying out of the foam and smashed into a hundred pieces on hitting the door. I added a few more yards of foam at that point. After that, I tried it with a video camera. I got a full tape of footage – although it doesn't really give a lot away.

"The trouble is that dimension bit. Because there's only one dimension of length, every part of the camera is effectively at the same point. The transformation between physical and temporal dimensions means that physical processes still work – like the tape moving in the camera – but every pixel of the CCD was effectively looking at the same point. The result is that the footage shows nothing more than the whole screen flashing different colours, and the audio track has an odd selection of wails and whines, burps, farts and growls, which will mean nothing to you.

"Of course, the fact that the camera had recorded anything at all was promising, so I'm sorry to have to confess that I took a trip down to the local pet shop. Still, the hamster seemed to survive okay, so I figured it was time for a human trial. And the human I chose, as you've certainly guessed by now, was me.

"I worked everything out carefully. I calculated the timings, and the deceleration rates. I tested the process using a selection of body building weights in the torso of a tailors' dummy, in order to simulate my own size and weight. Every time it just plonked gently out of the foam, perfectly intact. Then today, just a few hours ago, I finally stepped into the accelerator myself.

"It was wonderful, Frank. The whole world just seemed to flex visibly in front of me, then it snapped past me, as though I had been pressed through a picture of it painted onto a rubber sheet. What was left was nothingness. Just a plain, block colour. No shading, no texture; wherever I looked it was the same. The colour changed constantly – sometimes fading slowly from one hue to another, sometimes flashing and strobing violently. I could move my muscles – or at least it felt as though I could – but neither turning my head, nor even closing my eyes, had any effect.

"At first I was terrified. It was like a nightmare come true. The light played nauseating tricks on my mind, and I was sure I even felt my stomach retch, but nothing happened. Now that I've had time to think it through, it's possible that perhaps I did vomit, perhaps I was closing my eyes, perhaps my head did turn, but every part of me was compressed down to a single line, dimensionless except in its infinite length, so the physical effects of vomiting were the same as those of not vomiting. Closing my eyes may have shuffled some atoms, or more likely shifted them in time, but there was no longer a concept of being able to shut out the light.

"And all around me were sounds. I don't know how to describe them in any other way, but that was the part of my brain that they stimulated. I found that I could make sounds, too – but not by pushing air past my vocal cords; just by thinking about the impression of sounds. At first I mimicked the sounds I was receiving, just by playing them back in my memory, but eventually I was able to construct new sounds at will.

"Time seemed to be passing slowly, too. I know that must seem like an odd statement, given that I've already said there are three dimensions of time, but one of them is still dominant – in much the same way that we travel forwards and backwards a lot more than we travel left and right. Anyway, it kept my own biological clock ticking to give me a vague idea of the time that was passing for me.

"It took a few days for me to manage sound creation. When I say 'a few days' you should be aware that I didn't sleep – not only would it have been difficult, given the flashing lights and disturbing sounds – but I also didn't feel tired in any normal sense.

"It was the day that followed when I began to realize that perhaps I wasn't alone there. I made a sound – mimicking another but adding some tentative elements of my own. The light flashed violently, and I felt a rush inside – not dissimilar to the feeling of weightlessness you get at the top of a roller coaster. I understand now that this was the result of something pushing me through one of the time dimensions. At first I thought nothing of it, not comprehending the significance of the light, given that it had been changing constantly since I arrived. It was only as I practiced my mimicry that a pattern emerged. Each time I copied the sound, there was a flash of light, and often a flutter inside – a push through time.

"Of course, it didn't take me long to recognize the existence of the pattern, so I began to experiment with variations on the sound, to see their effect. It quickly became apparent that the response I was getting implied some sort of intelligence, some sort of creature, was there with me. I tried to work out some sort of logic behind the sounds and flashes, but it was so alien to me that I had little hope of comprehending.

"I began to wonder more about the rushes I had felt in my one-dimensional stomach. Perhaps I hadn't felt them there, but only thought I had. It was a philosophical conundrum, but I supposed that I had experienced some sort of external impulse beyond my comprehension. Naturally my brain had to attribute some label to it, so concluded that it was similar to the effect of the roller coaster. Once I had accepted that there wasn't necessarily a physical reason for the feelings, I began to consider the other possibilities. It was then that I realized that I might have been feeling movement through one of the other dimensions of time.

"I figured that if I was going to survive here, it might be useful to know how to make such movements of my own volition. For weeks I tried, imagining the feelings, trying to coax my body – which only existed in my mind, after all – into twitching internally. Eventually I succeeded in leaping around in fits and spurts, and with each movement came a change of colour. But without a greater understanding of what I was doing, the exercise seemed pointless.

"Eventually, maybe a month or more after my arrival, I had a breakthrough. I can only explain it as being similar to my time at school when I was learning about binary arithmetic; I just didn't comprehend it, and was lagging well behind the others, then one day it all seemed to snap into place, and within days I was racing ahead into hexadecimal and beyond. Anyway, the breakthrough I had was that I developed the ability to see more than one colour. Well, not actually 'see' as such, but to know where and when they were. I could aim my time-travelling stomach jolts towards a particular colour, and generally get fairly close – but the great thing is that I would actually know how far away I was, and with subsequent jolts could eventually move there.

"I know it all sounds odd – and if I were to explain it in detail, and with all three time dimensions, you could never understand it – but perhaps if I explain what I finally discovered about that world, things will become clearer. Firstly, as I have said, there is only one spatial dimension. The colours I saw were objects in that world coming towards me, or receding away. The changes of colour took place when one of those objects moved through one of the time dimensions. Effectively they remained in the same place, but moved to a time when I was not in the way. Of course, when they did that, whatever was behind them would be revealed – hence a different colour came into view.

"The flashing colours, as I eventually found out, were equivalent to waving, shouting or tooting your horn at someone who is in the way. It seems that until I learnt to control myself in that world, I was spread over enormous tracts of time, which got in the way of the creatures that lived there. They naturally communicated in the only way they knew – predominantly by colour, but with sound taking the place that gesticulations occupy in our own world. That's why I managed to enrage one of them by mimicking its sounds; it transpires that it was gesturing me with their equivalent of a two finger salute – which I just repeatedly threw back at it.

"But that's another thing – my use of the word 'it'. You'll find that I use 'it', 'him' and 'her' interchangeably, as the creatures themselves do not have a concept of sex as such. They mate and reproduce, certainly, but not by a physical process that relies on differences between groups of them. In fact their whole method of reproduction seems, to me at least, to be far more effective and certainly far more cerebral than our clumsy fumblings could ever be.

"But how do I know so much about their culture? Well it so happens that after a few more months I finally made a breakthrough in communications with them. My travelling had become more and more accurate, to the point of being nearly instinctive, and I was aware of my surroundings, and of the meaning of colour, to enough of an extent to avoid landing on or in things. You see, it is perfectly possible to jump to the same point in time as something else, at which point it either breeds with you, or becomes displaced into another time itself. The latter case is what happened the first time I felt the fluttering in my stomach – my gesticulating friend was essentially pushing me around, although I was too unawares to know it then.

"Once I knew where things were, it was a small step to 'sensing' around their extremities, to get a feeling for their shape. Of course, their shape is a temporal concept to them, but I still tended to visualize things in the spatial terms that I understood. Once I could determine the shape of things, I could begin to work out where one object stopped, and another began. Then, like a child learning to identify things, I began to associate certain shapes with one another, and to notice the similarities and differences between them. Ultimately I began to notice how they moved through time – or how they didn't – and hence began to get a feel for which objects were inanimate, and which had a will of their own.

"It was a long, hard process – and must have taken several years before I really started to comprehend not only the basic difference between animate and inanimate, but also between animate and instinctive, and animate and intelligent. I tried communicating with more than one of the tachyon equivalent of voles before I got that one sussed.

"Eventually I could identify the 'people', and from that I could identify what changes of colour went together to form words. I noticed the colours that exchanged when two of them met, and found a repetitive selection of hues that represented a greeting. From that basic building block I was able to slowly, shade by shade, construct whole words and sentences, until after about ten years I had become a recognized member of their society. 'The foreigner' they called me – on account of my strange temporal shape – but they were universally friendly, and incredibly tolerant of my basic grasp of their culture and language.

"For years I was a local curiosity. High ranking officials from other states or even other countries (all defined by their proximity in one of the temporal dimensions) came to visit me, to learn of the peculiar world of simultaneous colours. I talked with the most learned of their professors and the most revered of their philosophers, and throughout I was treated with nothing but the utmost respect.

"It was during one such visit, to the University of FCFFBE05;EE83AA0F;DA90FA00 (my own 'alphabet' based on 8-bit values to represent the principal colours and the transition times between them) that I met an undergraduate called FFFFFF05;72FAFA05;72FEFA05;05138D00 (a name that looks far more beautiful than this clumsy alphabet implies). I shall refer to her as 'she', in part because her personality had traits that we would associate with females, and in part because of the relationship that formed between us naturally implying that she was female, given that I am heterosexual. She was different to any of the other students, or indeed tutors, that I had met during my time there. In fact, she was different to any of the other people I had met. How fortuitous then, that she should have been assigned to show me around the facility, and to ensure that I was made comfortable.

"Naturally we had lunch together, during which time we talked endlessly (one of the advantages of the strange physics of the world is the ability to 'eat' and talk simultaneously), and it became quite clear that, despite my bizarre frame, she was falling for me as much as I was falling for her. Suffice to say that we met up after I had finished my presentation, and then began to see each other on a regular basis. You can have no idea how wonderful it is to be freed entirely from the baser urges and to have a relationship that is, and can only ever be, spiritual and intellectual in nature. It was not long, therefore, before we fell in love.

"And now I near the end of my story. We made a commitment to stay together forever, and although they do not have a marriage ceremony as such, the local mayor – with whom I had become quite friendly – agreed to perform the ceremony (as best I could remember and translate it) for us. We moved into my house – which was a spacious affair, given that I could command almost any fee for my after dinner speeches – and lived in relative tranquility for the next twenty years or so."

His eyes began to well, and his head dropped once more onto a knotted mass of fingers. In loud exhalations that physically moved him, he began to cry. Occasionally he tried to lift his head and utter a little more, but each time he began to choke on his words. His lips were moistened with the warm salt of his tears, his eyes were reddened by the same. Eventually he resigned himself to a fit of sobbing. All the while, the camera rolled on.

"I'm so, so sorry. You can't really comprehend what this is like for me. Not having possessed a body like this for so long, it is still difficult for me to control it. I feel like a child again; like a toddler, maybe, both in gait and in my inability to suppress tears in favour of words.

"You, Frank, will no doubt have guessed at the ending of this tale. But for the benefit of the police, I shall do my best to continue to its conclusion. As I have already said, we were happy together – never wanting for anything, and so perfectly compatible that we rarely even argued – although we did enter into lengthy debates quite often. During my time there I almost began to forget my previous existence. In fact, I'm sure that I would have done, were it not for my storytelling on the lecture circuit, or my bizarrely hulking frame, spread obscenely over all three temporal dimensions rather than the more delicate spread of two that described my wife.

"I had been there for forty-three years, by my own reckoning. I have little doubt that the figure is inaccurate, and the fact that there was no requirement for sleep made my designation of a "day" somewhat arbitrary, but regardless of the technicalities, I was there for a very long time. And yet all that time was just the merest fraction of a second in our own world.

"It was earlier today that things changed. I mean "today" in the tachyon world, as this whole affair has occupied far less than a day in this one. It was what amounts to an evening there – a period of the principal timeline set aside for rest and relaxation. My wife and I were entertaining friends, making a total of five of them, the tachyon people, and our three pets within my immediate vicinity. We had just "sat down" (i.e. we had all come into temporal proximity, in the same way that you might move spatially closer to your friends in an intimate setting) and were starting to set the universe to rights, as we often did.

"It was then that something horrendous occurred. The whole event took place so rapidly that it is hard to describe. I was the first to notice; the end wall of the room started to bow outwards in time, ever so slightly. Before I could speak, the effect had become more pronounced, and my friends noticed it too. The pets were flashing wildly with fear, and even my usually calm wife was cycling worryingly from blue to green and back. The bow grew and grew, pulling first the one wall, then the other walls, the floor and the ceiling away from us. The stretching was visible in the way that time became distorted, and we could see the rift creeping its way along the room towards us.

"We tried to run, but as soon as I moved, the whole effect moved with me – as though I was its focus, its epicentre. Naturally I warned the others away, but my wife refused to leave me. Our friends tried to make it to the door, but as they approached it from one side, so the distortion approached it from the other. They made it out just in time, but our pets were trapped in the room with us. My wife clung tightly to me, begging me, as a man of science and a traveller of the universe, to explain what was happening. I should have twigged immediately, but those forty-three years had dulled my mind, and I could offer no explanation.

"Finally the effect began to creep around my extremities, in the dimension that my wife did not share. I felt an incredible pull – not painful in any way, yet so strong that I could not fight it. I saw my outer edges being stretched to infinity, as though they were made of elastic. Then it reached my wife. She too was pulled and stretched, but the vibrancy of her screams told me that to her the process was far from painless. She shaped her words in colours far more intense than any I had seen her use in the past, begging me to help her. But there was nothing I could do, except sense her stretch further and further away, screaming and crying all the time.

"And then the world snapped past me – as though I had been pressed through a sheet of rubber. Suddenly I was moving through an unfamiliar world where I could see a multitude of colours at once. Something engulfed me, clinging more and more firmly until I finally wrested free of its grasp, and was brought abruptly to a stop by the cold metal of the hangar door.

"When I finally regained some control of my body and mind, I interrogated the computer. As I now understood, I had been decelerated. But it also confirmed my thoughts about my wife. You see, she too had been decelerated, but she was constructed entirely of tachyons. As I said at the start of this tape, tachyons cannot exist at sub-photonic speeds. My wife has been killed, eradicated from the universe by my own machine.

"Although unintentionally, I am nothing short of a murderer. So I have to make amends – not just in this world, but in theirs. Goodbye Frank."

It was almost five hours since Professor Francis Jacobs, known as Frank to his friends and colleagues, had arrived at the university. He had been greeted, as usual, with a cheery hello and a fresh cup of coffee from his secretary. She also presented him with the morning mail, already filtered for junk.

"There's an interesting one that's come through the internal post, Professor. A video tape."

Frank had been intrigued enough to take the tape straight down to the AV room. He watched it, astounded by what he saw, then sat for a while mulling over the implications. Four hours ago he rang the police. One and a half hours ago they arrived. He'd shown them the video, directed them to the airfield, and waited.

At long last, they returned.

"So you say you've not been out there yourself, Professor?"

"No. I called you as soon as I realized what he'd done."

"Probably for the best. A messy affair, it has to be said. We're not treating it as anything other than suicide at the moment – although obviously we have to continue our investigations, just in case anything else comes to light."

"How did he do it?"

"Pardon?"

"How did he do it? I mean, did he hang himself? Electrocute himself? What?"

"Oh, I see. Well from what we've gathered so far, he sent himself back through his machine. Only this time, he didn't replace any of the foam. With the speed he must've been travelling at – well, let's just say that the hangar doors didn't fare too well, either."

"Well, if he doesn't make it into any scientific journals, he should at least be remembered in the Guinness Book of Records: simultaneously the fastest and slowest suicide in the world."

The rights to all of Xav's stories are available for films, television or audio recording. Well, it's worth a try isn't it? If you're interested, I can be contacted as:-