Big Jo has said that she wants me to tell her about how things were. She's going to write about it.

I used to live alone. My world was such that I could sit down, or crawl, but could not stand up or lie flat, at least with my eyes open. Sometimes when I closed my eyes I could lie flat.

Sometimes when I opened my eyes I could see me, sometimes I could not. There seemed to be no pattern in when I could see, except I could see when food arrived. I would cup my hands, and lift the food to my mouth.

Sometimes when I was laid flat, things would change. Once it became that I could see through one of the walls. There was another like me there. They had a colourful splodge on their forehead. I might have too – I've never seen it.

I don't know how long I was there. It was how things always had been.

My name is Jo. I used to live in Neverno. I suppose you've all heard what went on there now. But I don't feel our story has been told.

Karen, Laura and I had the perfect upbringing. We were intelligent, fit and everything was available to us. It wasn't unusual for us to be taught on exercise bikes.

When we were about 12, we started having new lessons. Human biology. They said we were changing, so we could become parents. I asked them what parents were. They seemed worried – they had said something they shouldn't have. Looking back I can see their dilemma – but at the time, it just confused me.

One day Laura picked her nose. It annoyed them for some reason. They shouted at us, we should not have disgusting habits. How did they know? None of them were in the room at the time. They must be monitoring us with cameras.

But how to find where the cameras were? We made a map. Everywhere that we were done for picking our noses [the habit had, intentionally, spread] must be within the beam of at least one camera. By identifying where we were undetected, we could work out where the cameras were.

One was hidden behind a mirror. Another in an artificial plant. I hadn't seen a living plant, except in biology and lunch.

Karen would keep the map under her blanket. We weren't usually allowed blankets, but it was very cold. When asked why, they muttered something about heating being broken, no funding for it.

One day, when we'd been in the gym, we came back to find our blankets gone – and the map. They knew. We had to act now.

We barged down the door and found ourselves in an aluminium-floored, clinical corridor. We knew that they'd know we'd escaped. However – they were paranoid. They had no cameras in their area, just in ours. There seemed to be few people about, so we walked quickly, but quietly. No need to cause alarm – or set any off.

You could leave buildings through doors. We went through one marked 'J'. It was full of computer workstations, monitors, and there was a box in the middle, only about a metre cubed. A wailing was coming from it. We took off the lid.

The ceiling went, and strange people looked in.

"It's only a monkey. Leave it."

That was Laura. She's not usually that cruel, but we all knew that we had to get out. I lifted the monkey up, and looked into its eyes.

It looked into my eyes, and I looked into its. She made noises – speech.

"Laura, it's not a monkey. She's me."

Little Jo was in a state. Malnourished, she was cramped in her metal box. She would have never seen the sunlight. Then again, neither had I.

Karen and Laura went further along the corridor, checking for rooms K and L. We opened a fire door, and found the wilderness. Karen and Laura came after us – Karen was carrying a Little, but Laura was not.

Little Laura wasn't there. Little Karen seemed even weaker than Little Jo. It was going to be cold out tonight, so we wrapped the Littles in our cardigans.

They wrapped me in warmness. I laid flat, like I thought I had before. There was another like me, almost like the one I had seen, but not quite. Her eyes seemed like one of the Bigs, while mine were like another. When I closed my eyes, I did not just think I was laid flat – I knew it.

Little Karen didn't survive the night. We buried her under a tree. At least she had one night of freedom. Little Jo, on the other hand, was much more awake than yesterday. Then Karen stated the obvious.

"We're hungry.

And so we were. There were four of us to cater for, and we had no food.

We walked for a few hours. Well, Little Jo was carried. Eventually we reached a road, and a place where food was being served. We tried to get some, but we had no money, indeed had no concept of money.

A truck driver picked us up. He had a newspaper, so I read it. It said about a mass breakout from Neverno, and that we were dangerous. There were blurred photos of Karen, Laura and I. I suppose that they didn't think Little Jo, or Little Karen, were worth looking for.

"You're them, aren't you!"

Rumbled. We prepared to flee.

"Don't be afraid! I'm one of the Neverno opposers."

"Who?"

"We believe that what was done there was wrong. They kept children trapped in boxes! And of course, the government never said what was really going on."

I unrolled Little Jo from the blanket that we'd kept her wrapped in.

"Oh my. They have been terrible to her, haven't they? But she has her twin's eyes."

"So you knew what was happening?"

"Only from Professor Greenacre. She was worried from the start. She thought that human rights should not be withheld just for the sake of an experiment."

"It's not a coincidence, is it? The Js, Ks and Ls, I mean."

"No, there were others before you. As, Bs and Cs didn't leave the test-tube. Ds, Es, and Fs didn't implant. Gs, Hs, Is died while they were babies."

"Test-tube?"

"You are clones of each other. They were trying to sort out, once and for all, the great nature v nurture debate. If you were genetically identical, then every difference would be due to nurture. Of course, they didn't realise there was a difference between variations in upbringing and neglect. They just wanted startling results."

"And they didn't care who they hurt to get them."

"No, no they didn't. Professor Greenacre spoke out, said it was wrong. First they ignored her, then they tried to silence her. Once they'd fired her, we knew it was true."

We got to the place. It was a small house, but it was full of people. He said that the news had spread. Everyone was happy that we were free. So were we.

They pulled us up onto some kind of stage, to talk about what had been done to us. Video cameras were running, normal cameras flashing, dictaphones, people taking notes. Everyone seemed more concerned with recording what we said than listening.

We've stayed in the safehouse ever since. We live in a small room. Every so often people come to talk to us, bringing their tape recorders. Little Jo has proper clothes now, and we have even taught her to talk.

I wish I could see the sun again.