One day, a girl walked into class and sat down, somewhere in between Teacher's Pet and Slacker. The day hadn't been particularly noteworthy thus far, and it seemed unlikely that anything would change. The girl wasn't that noteworthy herself, being the kind of person you meet and then almost immediately forget. She didn't even notice; that was just the way it was.

It was time for Math, and the girl was already bored. It wasn't that she disliked Math. It just seemed to her that she could be doing something more productive. It wasn't as if she was ever going to need it again, after all. Math was for smart people, people who grew up to be Doctors and Lawyers and Scientists. Not for people like her.

And then the lesson began.

It was just like any other lesson. The teacher stood at the front of the class and started to drone on about such and such an equation with such and such parameters, all the while scribbling on the overhead projector that was always just a little out of focus. The girl didn't really pay attention at first. It didn't matter to her, so long as she passed. She could get someone to explain it to her later.

Slowly, however, ever so slowly, something began to worm its way into her head. She began to look at what the teacher was doing, to really watch. She looked at the meaningless numbers and letters, jumbled together seemingly at random, and then she looked at the image they supposedly created, and slowly, slowly, the two began to make sense. Not in the way the teacher explained it, no, that was just as meaningless as it seemed, but still… The chaos in her mind began to give way.

On the blank page before her, a world appeared. A pair of thick black lines divided up from down, and right from left, good from evil. There were dimensions to it, more than the drawing could ever show. Most of it was filled with vast, empty space, marred only by the faded blue lines that streaked across it like never-ending shooting stars. The teacher called it a 'Cartesian Plane'. At the top, she gave it her own name in big block letters, pressing hard enough to leave a memory of the word on page after page beneath it.

She inscribed the rules of this world to the side, just beyond the boundaries of the Plane where no-one could see. She found that each number, each letter, had its own meaning, its own reason for being on her little universe. This one gave it gravity, that one determined inertia. In a flight of whimsy, she added in an extra eight that would become the number of Magic. Together, they were the abstract representation of the actual, as real as the space spiralling out before her, and even more important.

And then, only after everything else had been completed, did she draw the line upon which all the world would rest. It went on into a theoretical forever, an eternal curve that was never completed. It seemed like an impossible thing, for a line to curve but never come together. And yet there it was, clear as day before her.

If anyone else saw the magic, they didn't show it. They seemed just as bored now as she had been a moment before, anxious to get on with their days. The girl found herself wondering how they could think of the world beyond the classroom door when they all had a world right in front of them. Could they really be that blind?

Time went quickly on the line. Within a heartbeat, great clouds of cosmic lead dust had condensed into suns and moons and planets, all falling inexorably towards the non-existent edges, rolling towards an end that would never come. Another heartbeat, and life had evolved, swimming amoebas growing into flowers and fish, birds and bees, dinosaurs and dragons. The mundane and the fantastic walked the eternal curve together, side by side.

Sentience evolved. The people of the girl's little world looked up into the blank, line-streaked sky and wondered if there was someone up there, looking back down. They marvelled at the world around them and made worlds of their own, worlds where girls walked into Math class and created yet more worlds. They spiralled outwards like a reflection caught between mirrors, each one inside the other and each one just as big as the last. Empires rose and fell. Epic wars raged, and long stretches of peace lasted thousands of years. Great heroes took it upon themselves to save the day, and although good didn't always win, it never gave up.

It was beautiful.

And then the bell rung, and the world was stuffed back into the backpack from which the worthless piece of paper it had been had been pulled, and the girl went on her way. For a time, she remembered her little world, but there were more important things to worry about than a daydream. Life got in the way, as life often does, and the land of magic and wonder was forgotten.

Years passed. The lines faded and blurred. The magic was lost, that extra digit erased by time and ill fortune. The paper became frayed around the edges, and the shooting star streaks were lost to an badly timed rainstorm, making the sky an endless, monotonous, faded blue. The world no longer thrived.

The people began to wonder what had happened to their God. There were whispers that they had been abandoned, left to their own cruel fate by a deity who had created them just to watch them suffer. They began to lose faith. They began to think that there wasn't anything to have faith in in the first place. Terrible things were done in those times, things which would never, could never be forgiven. It was a time of darkness, and a time of loneliness.

Little by little, the girl's gem of a world began to die.

One day, when the girl was no longer a girl, her young daughter came across the paper, tucked safely away in her old yearbook where she was almost guaranteed never to look at it again. Her daughter brought it to her, smudged by apricot fingers and more than a little worse for wear, full of questions and wonder at the world inside the page.

For a moment, the girl didn't remember. It had been so long ago, and the magic had faded years ago. It looked to her like just another pointless exercise, just more practice to perfect skills she would never use again. She almost threw it away.

And then she saw the name she had written at the top of the page in letters so deep they scored sheet after sheet, and she remembered.

Just like that, the magic was back. The world open up before her like the classroom door, leading her into a place that was both familiar and strange. The years had coloured her perceptions, and the world itself had changed much, but the strong lines of the plane were the same. The rules were still there, just beyond the borders of the universe. The curve still went on and on into that theoretical forever. It was all still there, just waiting for her to come back to it.

Her daughter climbed into her lap, running sticky fingers over the worn paper. Her finger traced the line of the curve, and the inhabitants of that world found themselves a new God.

Smiling, the girl who was no longer a girl began to show her child what those numbers meant.