There was no warning at all: no signs or portents. Indeed, I only have Quarp’s say-so that I was headed toward my death that day.

It was my last train. Well, yes, it was my last train period, but for that day’s roster it was the completing journey: a snip of a job, returning an empty train to Wimbledon Park Depot. I didn’t even have a guard; it was DOO - Driver Only Operated. It was only eleven in the morning but I’d started before four. It was a cold, clear day, sky of blue above Malden suburbs still dusted with frost. The track was thrumming beneath my train as it pounded along at a steady sixty, the rhythm of the track joints like a cantering horse: a pleasant association not lost on me.

The AWS sounded harshly as I approached a signal: single yellow light - the next would be red, but it was a long section and there was no need to brake yet. I canceled the warning and shut off power.

And then the sky dimmed, and the world went grey, and I was suddenly wrapped in the cotton-wool embrace of the thickest fog I had ever seen. I blinked, quickly but gently applying the brake: the class 455 unit I was driving was notorious for sliding in damp conditions. I could see only a few yards in front of me, but I wasn’t unduly concerned: the red signal would still be some distance away and the train obligingly slowed until we reached a cautious ten mph, where I let her coast along. Then I spared a thought for the fog: it was amazing! perfect visibility to impenetrable in the space of seconds. And it wasn’t the weather for fog. Well, it hadn’t seemed the weather for fog...

Something appeared at the track-side and my hand tightened on the brake handle, but it wasn’t the signal. At least, it wasn’t the signal I had been expecting: it was one of the small, knee-high shunting signals we call “dummies”. A small indicator above it showed the illuminated letters “TQ”.

I stopped the train. The dummy showed a proceed aspect: two diagonally placed white lights, but that wasn’t the problem. I was intimately familiar with this section of track. I had no memory of this signal being here. Dummies are used to regulate shunting movements: they are usually close to points leading to sidings, or platform loops. The next set of points on this line was Chessington Junction, beyond the expected red signal, and there were no shunting signals there that I had ever seen.

Ignoring the highest credo of any train-driver (if in doubt call the signalman) I released the brake and crawled forward, slamming in the brakes again as a set of points came into view. Points facing me. Chessington Junction’s points were trailing: facing away from me.

I must have gotten lost: fallen asleep or something. Now I punched the call button on my cab radio, but the set bleeped and the tiny message panel flashed the legend, “RADIO LOST”. Perfect.

Unhappily, I let the train roll forward again, grateful that I wasn’t carrying passengers. The points led me onto the left hand route, but I had no idea where that might be taking me.

Not far as it happened. The train was scarcely clear of the unidentified junction when the fog roiled and cleared briefly in front of me to reveal buffer-stops just ahead. I cursed and halted the train. Slamming the master switch to off, I popped the cab door and climbed down to the track-side, shrugging into my hi-vis vest as I did. I was in for it now. By railway regulations, going the wrong way, even if the signals show clear, was a major safety violation, and this would mean a full disciplinary action. I looked around, futilely searching for a ‘phone.

“Good morning.”

My heart almost leapt out of my chest. I spun about, staggering on the uneven ballast as a tall figure stepped out of the fog. I stopped worrying about disciplinary action and began to worry more about my sanity. Maybe it wasn’t Gandalf the Grey, but the fellow before me could easily have been his long-lost brother. Flowing cloak, tall conical hat with the wide floppy brim. A long white beard. Even a pipe.

“Please don’t be alarmed,” he said mildly. “I know you must be a little confused right now, but there really isn’t anything to be concerned about.”

I stammered incoherently as my brain tried to demand explanations whilst reprimanding someone who obviously wasn’t a member of railway staff for being on railway property. “Whar..?” I said. “Who..?”

“My name is Quarp,” he said, offering his hand, which I shook out of reflex. “Thadeus Quarp. And in a manner of speaking, I’m here to save your life.”

I didn’t believe him of course, and at first I was quite angry. According to this Quarp person who was indeed, so he said, a wizard, my train had been headed for disaster. Freak conditions had caused a build up of ice on the railhead in front of me. Instead of stopping at the red signal, my train would have skated forward onto the junction, derailed and hit the oncoming Epsom service, killing me instantly. So he said. It was a little difficult to accept in this tranquil island in the fog. I found myself edging back against the comforting flanks of my train.

“But you don’t have to die,” Quarp said. “That’s why I’m here. Ordinarily you’d just die, and that would be it, but I’m here to offer you a second chance.”

“You’re my guardian angel?” I asked sarcastically.

He didn’t take offense at my tone. “If you like. It would be more accurate to regard me as a sort of recruiting agent though. You’ve been head-hunted. You satisfy the rather unique requirements I happen to have need of.”

“Which are?” I prompted.

“The major requirement is that you are about to die in this world,” he said. “You mustn’t be missed. There must be no flaws in continuity.”

“In this world?” I repeated incredulously. “There are others?”

“You know damned well there are others,” he said sternly. “If your mind weren’t so contaminated by the close-minded stupidity that passes for common sense in this day and age, you’d admit that. I represent one of those others: one with which you’d probably have a great deal more sympathy for than this.

And he told me about his Earth, and how considerably more flexible natural laws allowed the reality of magic. A land with dragons and castles, and wizards and Unicorns...

Unicorns.

It was crazy. Of course it was. But...

I was in a great deal of trouble already. How much more trouble would I be in if I followed this stranger? It could hardly make a difference. Because I knew damned well that, however wildly improbable his story might be, it would torture me forever if I didn’t here and now determine the truth of it.

“Okay,” I said cautiously. “So where do we go from here?”

“Follow me,” Thadeus Quarp said. “This fog, as you doubtless guessed, is artificial, and serves to hide the passage I created between your world and mine. It’s just a few hundred yards. What did you think of my phantom siding by the way? Pretty good, huh?”

Shaking my head, I followed the strange man. I was unable to shake the slight qualm I felt as the familiar outline of the 455 unit faded into the billowing fog.

“You said you’re some kind of recruiting agent,” I said. “Recruiting for what?”

“Oh, the usual,” he said airily. “I need a hero to turn back the demon hoards, kill an evil dragon, find a cure for the deadly plague that afflicts the people. That sort of thing.”

I laughed. “No problem. And what shall I do in the afternoon?”

He paused and gave me a disapproving look. “If you could wield a sword like you do sarcasm, lad, you’d have no equal. Do not fret. It’s your soul that’s of value. You may not be suited to deal with my world yet, but you have a feel for it: you know the sort of things to expect. Storybook justice sometimes does prevail where we’re headed.”

“‘Sometimes’?” I repeated.

“Well, okay, sometimes you just have to wade in with a sword and cut the bastard’s legs off,” Quarp admitted blandly. “What do you want? An easy life?”

Abruptly the fog rolled away to either side. I stopped and stared. Quarp smugly twirled his white mustache.

It had been late morning in London. Here it was a little after dawn: the sky was glorious shades of rose and gold. We stood overlooking a broad valley filled with beautiful woodland, and on the opposite slope, straight out of Cinderella, a slender castle of white stone craned delicate towers of ivory to the sky. It was a breathtaking view, but that wasn’t what had arrested my attention.

“Ah, yes,” Quarp said. “Beautiful is she not? Tatheryn, first lady of all the winged horses. She always flies the dawn vigil. Imagine such a one as she as your steed, lad. Nothing could ever hold you back, hmm?”

High over the valley, effortlessly wheeling on invisible currents of air, was a great white horse with vast swan wings. Now and again she would lazily thrust at the air with a single down-sweep, and her legs would gracefully move in unison, leaping over empty space. An impossible long mane and tail drifted like veils in her wake.

We made our way to the castle: Quarp’s castle, Tir Ranis. He explained his proposal while I tripped over roots and bumped into trees, trying to keep the flying horse in view. It seemed all his carefully groomed and prepared heroes and heroines could not avail here, no matter what protection or aid he gave them. They were too well known, and being born to this world, were understood too easily by the enemy, many and varied though they were. It seemed he thought I would be sufficient to throw them off balance.

“Sure,” I said, gesturing at my South West Trains uniform. “I’ll just say ‘Tickets, please,’ and they’ll be so mortified at not having any, they’ll surrender on the spot.”

“Lad, of course you don’t look the part yet,” Quarp said patiently. “I said before: it’s your soul that’s valuable. We’ll just stroll on up to my laboratory and work a little magic. You’ve read all the fantasy epics, yes? Tolkien, Eddings, C. S. Lewis?”

“Pratchett,” I offered.

“Ahem,” Quarp said. “Much as I like a good satire, that’s not entirely what I had in mind. No! Haven’t you ever imagined yourself as the great fantasy hero? Master wizard? Swordmaster supreme? Elfland king? I can do that, lad! I can set you up with the body, the skills, the works! A scantily clad amazon wife it that’s your taste.”

“I’d rather stay male,” I murmured.

“A-ha,” growled Quarp. “Very droll, lad. No! I’m telling you: I’m one of the foremost powers in the land: I’m almost good enough to take our problems on myself. With you as my agent, augmented with my powers, you’ll easily be a match for any number of demon armies or dragons or plagues.”

I was doubtful, but so entranced by the winged horse that I didn’t really give the thing serious thought. I followed Quarp up a winding road to the castle, and in. We lost sight of Tatheryn, but there were further wonders in the castle: elves, slender and graceful with almond eyes and pointed ears (I resisted the temptation to cry, “Live long and prosper!”). There were blue-skinned giants; people that appeared generally human but had animal heads; satyrs, goat legged and horned. I saw my first centaur, and was tied between wonder at her biformed nature and goggling at her impressive and entirely unclad upper torso.

It was soon evident that Quarp was indeed master of the castle, from the way all others deferred to him. He bawled orders and everyone scattered to obey, be they elf, giant or centaur filly. I felt very much out of place, and was somewhat relieved when he gestured me to follow him into one of the towers.

We climbed for what seemed like ages up a tortuously steep spiral stair, emerging at last into Quarp’s magical laboratory. Its nature was obvious as soon as I beheld it: a cliché straight out of classic fantasy; ancient tomes; bubbling retorts, strange stuffed creatures.

“Right, lad,” Quarp said, shedding his cloak and tossing it carelessly into a corner. “Let’s get you settled, eh? I’ll get things ready: you think about what I said. Just imagine yourself as one of the heroes you’ve read about. Or heroines... oh! No, you said, you want to stay male. I understand, I understand...”

I thought about it while he gathered bits and pieces, mumbled over leather-bound volumes, and drew strange symbols on the floor. I was a little perplexed. Truth to tell, though fantasy was undeniably a strong interest of mine, I never actually had imagined myself as a great hero. Or heroine. My interests lay in other directions...

“Okay,” Quarp said, regarding his preparations critically. “That should do it. You come over here, lad. Mind the chalk marks: don’t scuff them whatever you do. That’s it. Stand in this blue circle here, and whatever happens, don’t leave it until I say so, right? That’s very important.”

I’d read enough about magical ceremonies, both fantasy and otherwise, to know how hazardous that could be. I nodded.

“Right. What I’m going to do here, to make sure no-one can undo any changes we make in you, is invoke the help of a minor demon who owes me a favour,” Quarp explained, pushing back his sleeves in business-like fashion. “Oh, don’t worry,” he said at my anxious expression. “As long as you stay in that circle, it can’t touch you. And using a demon, the change will be real: unalterable. If I did it, a good wizard could come along and say, ‘Dispel’, and poof! You’d be back as you are now. Quiet now. here we go.”

I swallowed. I was entirely convinced now that Quarp was who and what he said he was, and that I was about to be somehow transformed. It was an unnerving prospect, and I had no time to come to terms with it. Quarp uttered a strange invocation in a particularly vile-sounding tongue, and a chalked design in front of me began to glow, the space within shivering like heat-haze. The air there darkened and then filled with a nebulous glow that congealed into a large, disembodied head.

So far as I could tell, the demon was female. Actually, she was almost attractive, but her skin was a deep crimson, and her eyes, though darkly beautiful, were slitted like a reptile’s and just as cold. The horns on her head were no budding lamb’s but sharp and barbed like a dragon’s.

“Well, Quarp. What is it this time?” The voice, though possessed of a quality that should have been seductive and pleasant, made me shudder. This wasn’t a good creature.

“I require a small favour,” Quarp said. “This young human here is to be assimilated into my world.”

“Difficult,” stated the demon (demoness?). “Against the Rules.”

“But you’ll do it,” Quarp said, a quiet note of steel entering his voice.

The demon suddenly grinned -a frightening sight. “Of course. Come human. Step closer.”

I swallowed and stayed exactly where I was.

Quarp nodded approval. “He’s more sense than that, Hellspawn. Now attend. You’ll open the way to conform him to this land. You will not hurt or harm him in any way, or anyone else on this plane. You’ll find the image of his new form in his thoughts, and you will neither add, subtract, nor alter anything you find there. Understood? Gift him with the powers, talent, and knowledge requisite to his new form. Do this, and your debt to me will be repaid, and I will summon you no more.”

“You ask a lot, Quarp,” the demoness hissed, turning her baleful gaze to me. Her cold eyes locked on mine, and I shuddered as I felt the touch of her thoughts on mine.

Hush, human, she sent contemptuously. Quarp knows his trade. A minor entity such as I cannot defy him. Clear your thoughts, and picture what you would be to me.

Unable to resist, I obeyed unthinkingly. An image, sharp and clear, firmed in my mind’s eye.

You jest! the demoness hissed in fury, her eyes narrowing, then widening. But no! I see it now. You really do mean that, don’t you! And Quarp knows nothing of it? She began to laugh: horrible hissing laughter that echoed through my skull. Oh, I’ll do that for you with pleasure! It’ll be worth it to see Quarp’s face!

Light exploded around me. I cowered, but despite its apparent ferocity, it didn’t harm me. Instead a warm, rushing sensation entered me and filled me. My clothing unraveled and spun away, vanishing like melting snow, but the knowledge didn’t concern me or embarrass me. A calm surety filled me; knowledge and wisdom far beyond my own but becoming my own. My body changed, loosing the crude, angular, bony structure it had held for so long and assuming a new form of gentle curves, flowing grace, dazzling beauty. Cloven hooves, burnished like gold settled to the ground before me; a mane and tail finer than silk tumbled and scattered on the air. Prevalent over all this though, was the burning, shining, whirling sensation upon my brow. Magic grew there, spinning into an intricate spiral that burst forth with a blazing light. It was an eye; it was a wand; tool; weapon; star; alicorn... I felt time slipping from me, acknowledging me as an equal and excepting me from its jurisdiction.

The light of my transformation faded, and I shone there in its stead.

Quarp’s face, true to the demoness’s prediction, was indeed a picture, and I shared a measure of her glee: his facade of confident, all-knowing, all-seeing master of magics had slipped several notches. “What... how... Demon! You broke your bond! I specifically said no trickery! You were to turn him into a great hero, not some pretty... animal!”

“Your instructions were that I use his own image of himself,” the demoness stated smugly. “This I did. You cannot blame me if his idea and yours were not precisely in alignment.”

“Not precisely in alignment?!” howled Quarp. “He doesn’t even have the same number of legs!”

“Quarp,” the demoness said. “You are a fool, and fool twice over at that. You gave the boy free rein to be what he wished: he took no more than that. You cannot complain that he is not what you expected. And if you’ll only stop and think for a time, you’ll come to realise that what he is now is more powerful by far than any mortal hero.”

“Argh!” growled Quarp in high rage. “Be gone, be banished, be burned! Get you back to whatever foul pursuit you were engaged in!”

“My pleasure,” purred the demoness, and the head dissolved into flame, but before it vanished entirely I heard her voice in my head again. Well done, Unicorn. In all the unnamed eons of my existence, none have surprised or amused me quite so much as you here today. For that reason, and that alone, I make your form everything it should be; no conditions; no strings. Go forth and be what you are.

And I did. Before Quarp had recovered his wits, my dazzling horn had swept his chalk designs to the four winds, while I myself spanned the hundred-meter distance from the tower window to the forest beyond the castle like a great arrow. I could feel the power burning in my horn and surging through this incredible new form. No demon army could stand before it: no dragon could resist it. And a plague? My neighing laughter rang throughout the valley as I ran like spilt sunlight toward a glade where, my new senses told me, Tatheryn was quietly grazing.