Dad always tells me that my school days are the best days of my life. Bloody stupid thing to say if you ask me, I mean if being chased, beaten up and having my head jammed into a toilet bowl and the toilet flushed is as good as I’m going to get out of this life, I might as well end it now right?

Actually it’s not quite as bad as that. Some days I even manage to escape the attention of the all-muscle-and-no-brain brigade altogether. Some days we don’t have to do PE, which incidentally I am seriously rubbish at. Some days we get to do maths and science and then I’m in my element. And then some days are like today.

I’ve been looking forward to today for some time now. It’s supposed to be one of the highlights of the school year and something massively special. The science department have arranged for us to visit a research lab, and not just some rubbishy place that works on how to make paint brighter or glue stick better. No this place has defence contracts; real science, the sort I want to get involved in if I ever manage to escape from this hole with something approaching an education.

It’s just my luck that most of the crowd who make my life hell have chosen to get on the same coach as me, but I am not going to let that put me off. I intend to enjoy myself today and hopefully say enough intelligent things that maybe someone will remember me in a few years’ time when I apply there for a job. Nothing is going to stop this day from being special, I won’t let it.

The coach trip is the usual hell of travelling anywhere with the more moronic element of our school population. On the up side the teachers noticed the crowd of troublemakers on our coach and put a few extra bodies on with us to keep order. On the down side I’m surrounded by the worst of them; front, back and across the aisle. They’ve already spent most of the journey whispering threats at me, and they’re now getting properly annoyed ‘cos I’m not rising to their bait. Josh Lamar especially has his crosshairs aimed my way, mainly I think because he got caught calling me something unrepeatably disgusting and earned himself a detention for it. Even so I’m going to have to make sure I stay in view of the teachers today and not give him a chance to ‘get even’ as he puts it.

Our convoy of coaches pulls up outside the centre. At first sight it’s dead boring, just loads of red brick buildings and a car park out in the middle of nowhere, but I bet it’s just a cover, like Clark Kent and Peter Parker hiding the superhero underneath. At the main building our teachers split us up into small groups, making sure that the prats are evenly shared between them. Josh hangs back to see which group I end up in before tagging along.

We traipse about from one lab to the next. In some they have some pretty stunning demonstrations set up with mini rocket launchers and flamethrowers showing modern technology at its most flamboyant, others are less spectacular and only really excite people like me who understand what the guy in the lab coat is talking about. We’ve been on our feet now for about two hours and the nine tenths of our group who don’t give a fig about science are getting restless and looking for a bit of a laugh. This current demo has to be the all-time winner for dullness. It consists of a flask half filled with a colourless liquid. Most of the crowd switch off as soon as they realise there isn’t going to be a big bang or bright lights, but there are one or two of us who think this is probably the most fascinating thing yet. The scientist making this presentation is a pretty woman wearing a smart blue dress under her lab coat.

“What you see in this rather ordinary looking flask is the result of three years of painstaking synthesis. This rather uninteresting compound is what’s known as a chromosomal modifier, a drug that can be absorbed directly through the skin which has the capacity to alter the body’s DNA to match physical attributes to an individual’s personality. We’re hoping that in soldiers it will enhance male characteristics to superhuman levels. It is our aim to give the soldier of tomorrow greater speed, strength, endurance, agility and aggression.

“Unfortunately there are side effects that we are working to resolve.”

I stick my hand up until she notices me and points in my direction.

“What kind of side effects have you recorded and how do you plan to counter them?”

“Those are good questions, but I’m afraid we don’t’ have answers to everything yet. The symptoms we’ve observed are massively increased aggression — that one was expected but not quite to the uncontrollable degree we’ve encountered, although we’re still hoping to overcome it with training — and something we call the pendulum effect, which is a problem on an entirely different level.”

While she was speaking I was edging closer to the front. No-one noticed Joshua sneaking his way round the back. Suddenly he’s standing up behind the desk with the flask in his hand and an evil smirk on his face.

“Hey pansy, you could do with some enhancing.”

“No wait, be careful with that.”

The beautiful scientist is holding up her hands. Josh sneers at her.

“What with this? Don’t make me laugh, this is just water. Here weedling, let’s see if it enhances anything other than how wet you are.”

He sloshes the flask in my direction, people behind me are diving either side, but Josh is too close; there’s no way he can miss me. The neck of the flask is wide and most of the contents make it out. They hit me in the middle of the chest and in the face. It’s not water, it feels greasy and it soaks through my clothes and into my skin.

I feel strange, tingly and from deep inside me a boiling rage I have never felt before is rising up consuming me. My clothes feel tight, my shoes are pinching my toes, there is a loud ripping noise and my uniform is in tatters, hanging off my suddenly much larger frame. A second tearing noise and my feet burst out of my shoes. The pain only serves to increase my rage. I take one step forward and grab Josh by the throat, lifting him clear of the ground, clear of the desk even. It would be so easy to snap his neck right now or to throw him through the window, through the toughened glass and down three stories to the car park below

And wouldn’t he deserve it? For all the times he’s hit me and kicked me and humiliated me, wouldn’t that be justice? His eyes are filled with terror and there’s a pungent smell that goes with the dark stain spreading between his legs. In the back of my mind a voice is yelling, screaming at the top of its lungs and yet I can hardly hear it.

“Don’t do this. You’re not a killer, he’s not worth it. Look at him he’s pathetic, he’s wet himself, he’s not worth it. Put him down gently.”

The voice is getting stronger, the rage is easing. I feel the snarl on my face slacken into a gentler expression and I put Joshua down, carefully. The moment he’s on the ground he’s scrambling away and out the door, the last person out leaving me alone in the room. I look down at myself, all but naked, seven feet tall and three-hundred and fifty pounds of solid muscle. Where had all this mass come from? Scientific curiosity overrides base animal instinct and I feel myself calming, collapsing in on myself, shrinking.

The beautiful lady scientist is back in the room with me. She has her lab coat off and wraps it around my shoulders.

“I’m sorry sweetheart, you’d better come with me. This isn’t over yet.”

She takes me to a quiet room. Something’s wrong. I’m smaller than I was when I started, slimmer and there are other changes too. My chest feels funny, sensitive, with bulges on it, and between my legs. I lift the lab coat out of the way and scream.

It’s a girl’s scream, high pitched and terrified. And well it should be, there is nothing between my legs. At least nothing that should be there.

“What’s happening to me?”

“It’s ok, you’re going to be ok. I’m afraid you’re going to have to deal with some changes though. You remember I talked about the pendulum swing?”

I nod uncertainly. I remember but I don’t understand what it has to do with this.

“The compound that was thrown on you changes your chromosomes in a way we have yet to understand. It responds to moods, making you more male and aggressive whenever you feel angry. I have to say too, with the amount that was thrown on you, it’s amazing that you managed to keep your rage in check. That other boy is very, very lucky that you have such self-control.”

“Ok, but what’s causing this?”

I indicate my new form. The Lab coat is hanging open now, but it doesn’t matter because she’s a woman too.

“This is the pendulum swing. As your emotions drop back to their normal level, the chromosomal flux changes your body to match. So far we’ve only seen the changes in two human beings; both times the compound came in contact with them by accident.

“In my own case, only a very small amount dripped on my bare skin, and with so little of it the change took place over several weeks. I have a very gentle laid back personality most of the time and the current theory is that my body stabilised with a form that matches my normal outlook on life; which is why I am now female.”

“You mean I’m stuck like this?”

For a moment I feel the anger growing in me and my muscles begin to expand. It’s frightening enough to cause the rage to evaporate and with it the changes to my body fade.

“Unless you can change your personality then, yes I guess that’s one way of putting it. Another is to say that you now have the body to match who you are inside, and the only thing you’re are going to have to watch is your temper, because every time you lose it, that monster will come out and you’ll have to use all your self-control to keep it from wreaking havoc.”

There’s a knock on the door and she answers it cautiously, taking delivery of a couple of carrier bags. She walks back to where I’m crying gently.

“That’ll be the female hormones. They take a bit of getting used to, but they aren’t so bad when you do. Come on, is this really so bad? I mean can you honestly say that you fit in with other boys? There are a lot of things I think you’ll enjoy about being a girl. Friendships are a lot closer and there’s lot of fun you can have with a group of close friends.

“Then of course there’re these.”

She upends the bags and from the pile of clothing I pick out a pair of soft lacy knickers. The rest of the stuff is brightly coloured and very pretty. A new feeling in me stirs, maybe this isn’t going to be so bad after all.