He shook his hands free. Reached up to his head.

No, wait! Don't touch them yet!

Why not?

You want to be able to talk again, right?

Yes please!

Then leave the wires alone.

Billy sat up, wondering at the lack of aches and pains. Time had stopped, and evidently so had his nervous system. The straps around his ankles fell away when he stood up, keeping a weather eye on the motionless woman, and taking care not to disconnect any of the wires attached to his head. He walked up to her and prodded her in the stomach.

Careful!

Why? I can do what I want can't I?

Not yet. We have work to do.

What's wrong with her?

Nothing. She's fine.

Are you sure?

I... I think so. It isn't important. Come over here.

Billy walked round Katerina, his heart thumping, expecting her to grab him at any moment. This was the longest the trance had ever lasted, he was sure of it, and it could all end in an instant. He was not in control. The box was. He would worry about that later. Imagination or not, he was now free, so he may as well play along.

Are you doing this? he asked.

Me? No. Okay. See that thing on the desk next to me? The thing that looks like a squashed infinity sign made of iron?

This?

Yes - careful! That's a powerful magnet! Keep it away from me!

Sorry.

You will be. You don't want to hurt me. Not yet, anyway. I'm going to send you some instructions now, so don't freak out. It's just easier than trying to explain with this stupid language.

Okay, I'm ready, Billy thought, not feeling at all ready.

It was like the rush you get after a particularly indulgent ice cream sundae. The thrill of throwing yourself down a steep hill in the snow on a small plastic tray. You know there is a barbed-wire fence at the bottom, and you're pretty sure you can stop in time, but at the back of your mind there is the tiniest niggling doubt that your calculations may be wrong. Billy saw himself in the room, holding the magnet against his head. He saw the exact angle and location he had to hold it. He knew that if he was slightly out of position, he might knock out another part of his brain, instead of restoring his speech.

He saw - no, he knew - the code he had to type into the keyboard. The purpose of programmes he had no understanding of. What the machine did, how it worked, and why it hurt so much. It wasn't like learning, the information just appeared all at once, as if he had always known. This was no simple brain scan. Every electrical impulse had been carefully recorded, mapped, translated into a computer programme that was an exact, working copy of Billy's mind. The machine had been comparing the recording to another scan labelled 'control', highlighting areas where there were differences. It used words like 'abnormal', 'extraordinary' and 'superhuman'.

Hey now, steady on! the box said. Remember why we're here? There's not much time. Don't worry about that stuff, I've got it all stored away.

Billy lifted the magnet with his left hand. Tapped in the code. Felt an uncomfortable buzzing in his teeth for a few seconds. Lowered the magnet. Stretched his jaw. Drew breath.

'Hello?' he said out loud, with a careful eye on his captor. Katerina did not move. She was still staring at the chair he had been sitting in.

There you go! Now isn't that better?

'Now what?' Billy said, picking up the box and holding it up to his face. The cartoon man grinned back at him.

Now? Now we leave.

'How?'

You know how. And then he did. He knew that the machines in the room were just a small part of a giant computer. His mind's eye followed the connections out of the room into the corridors. The control system for the doorways. Security cameras. He searched and saw that Davey was there, somewhere in the building, frozen in a futile struggle against a door with no handle. Billy reached out to the door and commanded it to open. He saw the lock move. When time went back to normal, the old man was going to get a hell of a surprise. Billy cleared a route between him and the old man, opening and locking doors, turning off cameras.

He wanted to explore the building further while he had the chance, but there was no connection to the other levels, just this one. He could not tell how Davey had got as far as he did, but saw a trail of unconscious security guards behind him.

Come on, kid. There's no more to be done. It's time to go.

'Wait.' Billy said, and his fingers began to fly over the keyboard. Images of labs and white corridors flickered on the screens. 'I need to find the other children. I need to find Alex. I can't leave her.'

Here, the box said, with a remarkably realistic impression of a sigh, and another wave of information surged down the wires into Billy's head. Images of stricken, frozen children flashed before his eyes, until he locked onto the image of a little red-haired girl, standing defiantly on the other side of a locked door, fists raised. She looked angry, and Billy imagined she was halfway through shouting something obscene. He unlocked the door, and then, because he did not know how long this was going to last, drew a rough map on a piece of paper, marking himself, Davey and Alex.

He unlocked the remaining doors. He hoped they would make it out. If not, he had done his best.

Yeah yeah, very noble. Now then. You know what to do. Billy nodded.

He took cover behind the dentist's chair. Then he looked up into the Shadow and found his fear and anger. It had a clear shape this time, a dark red triangle with little circles in the corners and a tiny cross underneath. A shape he recognised, but that was not important now. Billy pulled all of his emotions from the last few days into a mass of twisting red-black fury and sent the resulting fireball hurtling down the wires from his head into the computer.

The wall of machines exploded.

The force of the blast threw Katerina into the opposite wall and she slid limply down to the ground, unconscious. A large hole with blackened edges appeared in the wall where the door had been, licked with flames.

Billy ripped the wires off his head, tucked the box under his arm, and ran.