That was close on four years ago.

In the intervening period, I've completed my BFA and joined Mom in the fashion trade, interning as her part-time assistant. We've met with unprecedented success in the past six months alone, opening up two new studios in Heartsfield and Greenmeadows. I'm still the junior partner in the business, of course, but Mom recognizes my artistic abilities, even while refusing to acknowledge my age.

In line with my academic pursuits, I've devoted a great many hours researching the background of my adopted world. Initially, I thought I was living in a mirror image of my home town, but as each month passed, I began to realize that there were innumerable differences between the two. Most were superficial variations on names and locations - Aunt Leisa as opposed to Aunt Lizzie; Chamberlain Heights as opposed to Chamberlain Downs. Other discrepancies were more significant - Ireland being a republic, Columbia being a District and Canada being a Commonwealth, for example.

In many respects, the general histories were identical: two major wars in the Twentieth Century, military conflicts in Korea and Vietnam, the rise of digital technology at the end of the 1980s. Almost all of the leading figures have the same names - John F. Kennedy, Neil Armstrong, Germaine Greer and Steve Jobs to cite a few prominent examples.

I suppose that the real differences are far more subtle, but I see them virtually everywhere I look nowadays. I said earlier that my Mother seemed somehow 'darker' in tone - a shrewd, calculating entrepreneur who would gladly drive the competition out of business if it suited her purposes. She's still my Mother, still warm and kind and generous by nature, but she carries an edge of steel I'd never noticed before.

Everything seems darker over here. This is a world cast in shadows of anger and conflict, as the merest glance at the online press can readily confirm. The daily news revels in horror and violence beyond anything I'd previously imagined. Mayhem reigns supreme at every level of society: from the highest echelons of government to the back streets of Hell's Kitchen. This is a far bleaker realm than the one I came from, a landscape blackened with hatred and drenched with venom.

Still, wherever there is darkness, there must be light. The contrasts between joy and sorrow are so vast that human speech cannot describe them. I've experienced both over the past few months, plumbing the depths of human emotion. Perhaps it was the shock of finding myself locked inside a female body, or perhaps it was the inevitable process of growing up - teenagers invariably suffer torment and rapture in equal measure.

Whatever the explanation, I've adapted to the demands of my new role. I have a far closer relationship to my Mother than Benny ever had with his. Yes: we squabble, we argue and fight like two scorpions in a jar, but the bonds we've forged between us are nothing short of indestructible.

Nor are those bonds confined only to my immediate family - Bianca Woodrow is far more popular than Benny Woodridge ever was. Back in Summerhill, I was something of a classroom phantom; a bland, nondescript boy who left no visible impression on the mind's eye. Here, I'm pretty, vivacious, outgoing; the cute little girl with the bubbly personality and the oversized folio perpetually clutched under one arm. All things considered, I seem to have gotten the better part of the bargain.

I have far more than just Bianca's memories. I've inherited her drive, her persistence, her ambition. Her prodigious artistic talent. Often, I look back and feel astonished at how little I accomplished as Benny, realizing how much I might have achieved if I'd bothered putting in the slightest effort. Over in the Homeside, I was lazy, lethargic and self-indulgent; here, there seems to be no limit to what I can do. Perhaps, like Bianca, I've acquired a taste for success.

I've been granted a fresh start, a second chance that I'd be a fool to squander. Very few people are given the opportunities I've been handed, and I intend to make the best of an extremely good situation. The future is laid out before me like a boulevard of dreams, and there are no obstacles to impede my progress.

Strange then, how much I miss my old life.

As mentioned above, this is a crazy, kaleidoscopic world, a place of excess and excitement. Having been here so long, I probably wouldn't give it up, even if I could. All the same, there are moments when I wax nostalgic for the people I left behind. It's the final paradox I've had to face: the knowledge that everyone I know and love is - at some level - a total stranger. Frances Woodrow isn't my Mother, Constance Radcliff isn't my best friend, and Leisa Newtown isn't my Aunt Lizzie.

The doubts and fears usually creep in around ten PM, after the day's work is finished and I'm getting ready for bed. I often look out the bay window into the night sky, winding down at the end of a long evening, when my mind is free to wander where it will. Almost inevitably, my thoughts circle back to the life I led as Benny Woodridge, and I catch myself wondering:

What's happening over there?

During my first few months, I made several attempts to return through the Mirrordoor, believing - no doubt naively - that the gate must swing in both directions. I reasoned that there had to be some kind of portal hidden away in the Alcove, an obscure passage between quantum realities, but my experiments always came to nothing. As I suspected, there was no way back. Perhaps the traffic can only flow one way.

I've spent many a sleepless night puzzling over this mystery. How did it happen, how did I manage to step sideways in time? What triggered the transfer, why did I come to this specific location in the space-time continuum? And perhaps most importantly: what happened to Bianca?

Initially, I reasoned that we'd undergone a complete transposition, swapped bodies through some momentary rift in the fabric of the universe. It seemed the most logical conclusion. However, a more frightening scenario soon occurred to me, one I didn't like to contemplate.

What if we didn't trade places? What if Benny Woodridge simply winked out of existence, vanished off the face of that Earth, never to be seen again? That would explain why I can't return, and the revelation haunts me in the dead of night. If my fears are true, then Bianca would have no host to occupy, no place to go. That would mean that I ... overwrote her, erased her consciousness, deleted her from this plane of reality.

In the warm light of day, I often imagine that Bianca is walking around in my old body, finishing the degree I never started and enjoying a life I could never lead. Sometimes, I actually pray that she made it to the other side, mostly because the alternative is unthinkable.

Of course, it's more than just Bianca I have to worry about. There's also my mother - my real mother, Fanny Woodridge; last seen disappearing over the crown of Summerhill Road more than three years ago. What is she doing now? How is she coping? Did I leave her all alone in that world? The thought of her coming home to an empty house, night after night, never knowing what became of her son...God, I hope they managed to find each other.

So many questions, so very few answers, and only the faintest chance that I'll ever know for sure. If, as I suspect, the door only swings in one direction, there's no way to tell what happened to my doppelganger. For the time being, I can only hope that I'll eventually discover the truth, one way or the other.

How? Well, I suppose that's the only question that matters now.

In recent weeks, I've considered the possibility that there may be others like me out there, trans-dimensional castaways thrown up on the shores of the multiverse. I may not be able to go home, but there's no reason why someone else can't come here. For all I know, I might be surrounded by hyper-spatial immigrants. If I'm ever lucky enough to meet one of them, then maybe - just maybe - the answers to all of my questions might be forth coming...