this was supposed to be a parable about the power of the imagination

"Look at your daughter. Look at her body language when she's out fetching water and then look at her when she's learning, crouched over the computer. I don't know what it is she has. It's like technological hyperopia. When that group of students came here it was the best thing that ever happened to her. The internet connection is the only thing that fulfils her because it's the only way she can get in contact with people who know things she doesn't know.

"The things she's looking at right now are called the Einstein field equations. They were discovered ninety years ago by a man called Albert Einstein. Einstein was probably the most significant physicist of all time. ...A, uh, a physicist is a person who studies physics. Physics is the way the universe works. It's the way things move about and interact with each other. Not the way I interact with you," he explains, in what Anoo Nkube's parents understand as passable Somali, "the way the smallest bits of the universe interact, on the very lowest level.

"She's looking at these equations. Do you know what long-sightedness is? Most people just see a blur. Some people are smart, or have had the benefit of education, and they see what the symbols mean and the obvious applications. And the derivations - the ways to get there and the routes onwards. But Anoo sees further than anybody. She has ideas which she didn't even know how to articulate until the students and their teacher arrived with their colourful mathematics books and this computer and modem. The word is 'savant'."

Mikhail Zykov's back begins to ache. He's too old to be sitting cross-legged for this long and he needs a drink.

The father's expression is impenetrable. The mother's is sceptical.

"You expect me to believe that you are acting selflessly?" asks the father eventually.

Zykov bows, acknowledging the valid point, and considers his response. "What will I get out of it? Think about everything we've said to each other. Think about speech. Speech is 'communication'. Communication is when information - a fact, a statement, a piece of knowledge - moves from one location to another. 'Information'. Anoo was telling me how everything has three things. Matter can't be created or destroyed. It can only be turned into energy. And energy can't be created or destroyed. It can only be turned back into matter. It's-- hard to explain. Anoo will explain all of this to you. You must ask her! She loves to explain things to people..."

"And the third thing?" asks the mother. She has always been more interested than her husband in the things her daughter discovers each day.

"Information is the third thing. Information is how much a sand grain weighs and how much energy the light ray carries. But information doesn't have to be conserved. When I tell you something, the information is now in two places at once. When I make something up, the information is completely new. And Einstein's mass-energy equivalence, ee equals em cee squared, can be extended to-- um--"

He's losing them. He drops down a gear.

"Okay. What will my government get out of it? Well, everybody dreams of a time when everybody in the world has all the food and water they need. But Anoo is closer to realising that dream than anybody in the world. The idea in her head is worth all the money in the world. That is not something I am just saying. All the money. In the world."

*

The way it was supposed to go:

Anoo Nkube, a teenage girl with no equipment besides uncountable stars and sand and no education besides a month's basic numeracy lessons from a group of British sixth formers and a 2400 baud satellite internet connection, derives, from what her teachers and friends and family can only conclude is thin air, a highly impractical but scientifically verifiable method of mass-energy conservation violation.

Ageing Russian science advisor Mikhail Zykov is the first man to sit up and pay attention to what half a dozen other eagerly-contacted scientists have written off as baseless pseudoscience derived from unproven axioms by an enthusiastic illiterate. The document's badly formatted and the English is bad and the MS Paint diagrams are bloated and crude. But the equations reflect the rules of the real universe more closely than anything previously seen in history. "Get me this woman," he says to the men who work for him. "Make this happen."

Lower the universe's temperature sufficiently and phase changes start happening. AC power for the birth of hydrogen. Selectively sized quanta go in. And one subpreonic particle turns into two subpreonic particles. Information equals energy times the speed of light squared. Build a big enough refrigerator and you can start processing passing tau neutrinos into raw preons of any of two flavours. Two is enough. From two you can build logic gates. Divert one into another and produce a third. Like mixing paint.

Zykov pulls strings. Anoo Nkube sheepishly explains what she wants in broken but rapidly improving Russian and he stands behind her and articulates what she says into concrete and precise instructions: go here, acquire these, construct this. A disused military-industrial site in Arkhangelsk Oblast is resurrected and retrofitted. This takes the best part of three years. Anoo spends half of that time at Moscow State University learning at a furious rate from physics and chemistry lecturers and the other half lecturing them in return. All this time, her focus and Zykov's is on the Dream.

The first warm-up experiment - cool-down, rather - is in late 2008. It's taken ten thousand hours of supercomputation to derive the construction process for the smallest machine modern science will allow to exist, but at the end of the long and sleepless night of 11th November the magic box contains a fully functional femtoassembler. Information goes in. And unbounded up and down quarks come out. The quarks glom instantly into hydrogen nuclei, free electrons in the atmosphere voluntarily neutralise the cations and finally the atoms bond together and become cold diatomic molecular hydrogen.

Per unit mass, it's a hundred thousand million times cheaper to get your hydrogen by electrolysing water molecules. Hell, per unit mass, it'd be more economical to catch and bottle hot coronal plasma from the Sun itself. But the first miracle always is the most expensive. Magic has a high initial outlay, certainly, but let me show you these "total cost of ownership" calculations--

By the end of 2009 a foot-thick pile of differential calculus has elapsed and larger atomic structures have been solved. Split the proton and pass information down the gap between the up and down quarks, and you can use it as a subatomic food processor. Argon krypton neon radon xenon zinc and rhodium.

Bigger, fitter, colder, happier, more productive. In 2012 an entire water molecule rolls off the zero-point production line. In 2013 it's a glucose molecule. Version three can produce twenty atoms at once. Version four can produce additional pipes and tubes, themselves producing arbitrary organic arrangements of hydrogen, oxygen and carbon. The structure of reality has become programmable, and the single most important instruction of all time is: "Become a computer..."

It takes the entire year of 2015 to make systematic destructive quantum observations of every atom in a microgram of wheat. By 2019 the square millimetre of particle routes and imperceptibly tiny self-organising magnetic fields is producing deoxyribose by the picometre slice. And now anything is possible. Water. Diamond. Air. Fuel. Buckyballs. Food. Computronium. Materials science impossibilities. Unbreakables. Space elevator cable. Wine. Lobster. Human eyes. All you need is the pattern and the patience to wait for the box to build a big enough version of itself. And, of course, the ability to stop drifting off into some imaginary science fiction future to focus on the present day for long enough to make the two ends meet.

In 2022, Anoo Nkube and Mikhail Zykov betray the Russian Federation. Complete and tested femtoassembler instructions are forwarded to a hand-picked thousand email inboxes. From there they go viral. The technology hundreds of now-unemployed people have helped them to develop goes from being Russia's most closely guarded industrial secret to the most widespread piece of information on the planet Earth. The Russian government has its vision of absolute and permanent economic superiority wiped out. Zykov is arrested, fined an impossible quantity of money and imprisoned for what will likely be the rest of his natural life. Nkube disappears without trace.

By 2025 everybody on the whole of planet Earth has free access to food, light, water, heat and medicine, the boxes are fast enough to create entire living humans from pattern and future history is no longer accurately predictable.

*

But then, just for a second when he walks in through the door, Anoo Nkube sees what's behind the mask of Mikhail Zykov.

He's exactly the same shape he always was, but it's like she stepped a little to the right and realised that the man everybody sees when they look at him is just a trick of perspective. From the front he looks like a human being. But from a little to the side, the human being is just the front end of something else, something huge and complex and black and ugly folded up painfully into an inadequate three-dimensional shell. A skyscraper whose ground floor is a human being but every other floor is filled with oozing alien organs and weird multidimensional sensors and wriggling feely things scraping against the metaphorical glass. Something like a compound eye focuses on her from above, and then closes up inside Venus fly trap eyelids.

"So let me tell you the real reason," says Zykov, sitting down at the board room table.

"You're-- not from here. You-- what are you? I've known you for years," says Anoo, backing away and beginning to panic.

"No, you haven't."

"Wait, wait, wait. All this time. It's coming back. You-- you said you worked for the Russian government. You said you were a spy. And then you said you were one of the cabinet's scientific advisors. And then you said this was a military project and you were a Russian general then you said it was about feeding the world-- every time I've asked you you've told me something different and... I..."

Zykov reaches into his jacket pocket and pulls out a folded piece of scrap paper, torn from a notebook. He slides it across the table to Anoo who realises that it is actually a page taken from a diary. Her diary. The page is from one of her first weeks in Russia and amongst the dense and inexpert handwriting the most prominent note, in the middle of the page, across Tuesday 16th and Friday 19th, is "WHO IS MIKHAIL REALLY??"

"I tore it out of your diary," he explains. "And I tore it out of your head. The same thing I do with anybody whose mind starts wandering off-topic. Information is nothing. Where I come from we can shovel it around like snow. You humans don't have much to work with, inside your heads or outside, but you've got the basic principles down. I don't work for Russia. I work for me. Everybody here works for me.

"'War' is too small a word for what I'm fighting. Like a candle in front of the whole burning Sun. I was crushed into your universe like a worm being pinned under a mountain. I condensed out here on Earth in this man's incomplete and stupid body because the human race was the first intelligent life, the first fountain of new information, anywhere in Alef. I need to get out, and for that, I need science. But I am not a scientist. So I need you. Using pretense and suggestion and occasional duplicity and this mask I have briefly removed, I have been collecting power and collecting knowledge and collecting people. That is what it has always been about. You are not the only project.

"Look at me. Look at what it's like for me to be crushed into this shape.

"I found you in Somalia because you had a spark; a radiant idea and an intellect that amplified it and made it visible for miles around. Your assemblers run on information, and information comes from intelligent thought. Your idea was to make a machine which turned ideas into substance. Your dream was a box in the village, and all the kids in the village reading stories to it at night, telling them what they did that day-- turning their creativity into clothes and fresh water. It was... so foolish, I had to know if it would work. And here we are."

The mind-breaking image in Anoo Nkube's mind wavers and disappears. Zykov looks normal again. She shakes herself. "It doesn't work," she stutters.

"No.

"Here's what's going to happen. Your hydrogen femtoassemblers are going to run out of control. They're going to build more of themselves, so many more that nobody will even have time to react. They don't know how to build more of themselves yet. But one of the technicians swears he saw an electrical discharge inside the Cage and I've seen that sign before and I know what it means.

"Within five minutes the nanometre-thick layer of assemblers will coat every free surface in the laboratory and the surrounding landscape out to a distance of at least a kilometre. It may even occupy some of Arkhangelsk city. It depends how lucky we are. Hydrogen will coat the assemblers to a depth of maybe a few centimetres - all over the walls, the floor, the ceiling, our skin, our eyes, the insides of our mouths, our lungs. And then there'll be a spark. It might be natural or it might be another act of God, I don't know. And the whole lab will go up and there'll be nothing left but shattered burnt bodies and water vapour. Hydrogen and oxygen makes water. The world's cleanest explosion.

"And before the dust has settled from the detonation replicator technology will have stopped working, anywhere in this universe, for all of time. And your dream will be dead."

Anoo knows he is telling the truth. "I wrote out an equation for the mass-energy-information equivalence," she says. She has tears in her eyes. "And I looked at it, and I thought, 'No, this is not right anymore. This was right. But now it is wrong.' How is that possible?"

"I told you. This is bigger than a war, and the person we're fighting is bigger than a world, bigger than a universe. Now, I am not going to die today. I have other projects, and other options. You can come with me. I can protect you.

"You can come with me. Or you can stay here and die with your dream."