Johnny pushed the door shut behind them, and listened for a moment.

" ... well, then ... bend and stretch and wheeze and bend..."

He straightened up. It was amazing what you could get away with. Ten-legged aliens would be immediately accepted in Blackbury if they were bright enough to ask the way to the Post Office and complain about the weather. People had a way of just not seeing anything that common sense said they shouldn't see.

"I bet something's gone wrong," said Bigmac.

"Er ... " said Yoless.

"No, this has got to be the 1990s," said Kirsty. "It's the only period in history when you wouldn't be burned at the stake for wearing a green and purple tracksuit, isn't it?"

The bulk of the sports centre loomed opposite them. Five minutes ago, thought Johnny, five of my minutes ago, that was a street. Get your head round that.

"Er ... " said Yoless again.

"They shot at me," said Bigmac. "A real bullet! I heard it hit the actual wall!"

"Er ... " said Yoless.

"Oh, what's the matter with you?" said Kirsty.

"Er ... where's Wobbler?"

They looked around.

"Oh, no ... " said Johnny.

They were Wobblerless.

"I ain't going back!" said Bigmac, backing away. "Not to get shot at!"

"He wouldn't have wandered off again, would he?" said Kirsty.

"No," said Johnny. "He must still be there!"

"Look, get a grip, will you?" said Kirsty. "You said the church doesn't get hit! He's okay."

"Yes ... but he's okay in 1941!"

"S'posing something goes wrong?" said Bigmac. "He didn't come back this time, s'posing we go back and all get stuck? I'll get shot!"

"You think you've got problems?" said Yoless. "I'd have to learn to play the banjo."

"Will you all stop panicking and think far a moment?" said Kirsty. "This is time travel. He's always going to be there, whenever we go back! Of course we ought to go and get him! But we don't have to rush."

Of course, it was true. He'd always be there, thought Johnny . They could go back in ten years" time and he'd still be there. Just like something on a tape you could play it, and fast forward, and rewind, and it would always be there. And later that night, the bombs would land in Paradise Street - and that night would always be there. Forever. Every second, always there. Like little fossils.

Kirsty hauled the trolley away and pushed it down the steps towards the pavement.

"His mum "n dad'll worry," said Yoless, uncertainly.

"No, they won't," said Kirsty. "Because we can bring him back to right here."

"Really? Why can't we see us doing it, then?" said Yoless. "You mean any minute we're just going to pop up with Wobbler and say "hi, us, here's Wobbler, see you later"?"

"Oh, good grief," said Kirsty. "I can't think about that. You can't think about time travel with a logical mind."

Yoless turned and looked at Johnny's face.

"Oh, no," he said, "He's off again... "

Everything's there waiting, Johnny thought. That's the thing about time. It doesn't matter how long it takes to build a time machine. We could all die out and evolution could start again with moles or something, it could take millions of years, but sooner or later someone will find out how to do it. It might not even be a machine. It might just be a way of understanding what time is, like everyone was scared of lightning and then one day someone said, look, you can store it in little bottles and then it was just electricity. But it wouldn't actually matter, because once you'd worked out how to use it, everything would be there. If someone ever finds a way of travelling in time, ever, in the entire history of the universe, then they could be here today.

And then he thought of the bombers, nosing through the clouds over the houses and the footballers and all those clean doorsteps ...

"Uh?" he said.

"You all right?" said Yoless.

"Let's get a drink, at least," said Kirsty, shoving the trolley firmly towards the town centre.

And then she stopped.

Johnny hadn't often seen her shocked. Kirsty normally dealt with the terrible and the unexpected by getting angry with it. But now she stopped, and went pale.

"Oh, no ... " she said.

The road from the old church led down the hill towards traffic lights at the bottom.

An overloaded shopping trolley, with a boy and a girl clinging to it, was hurtling down the other road.

As they watched, it heeled over like a yacht tacking against the wind, turned a full ninety degrees, and plunged into the car park of the Neil Armstrong Shopping Mall.

A long black car followed it.

He'd forgotten all about the car. Maybe there were secret societies. Maybe there were men in black in long black cars who said things like, "The truth is out there" and came and found you if you got your hand trapped in the occult.

Johnny could see a map in his head. But it was a map of time.

They'd moved in time at his house. But Yoless was right, you probably could move in time like a train on a track, so you flipped over onto another track just a little bit further along. You moved in space, really.

And he'd done it again, when he thought they were going to die at the traffic lights. And the black car had vanished ... because it didn't exist in this time. He definitely hadn't seen it when he'd looked behind him.

They'd come back to a time when it existed.

The car pulled to a halt outside the mall.

A feeling of absolute certainty stole over Johnny. He knew the answer. Later on, with any luck, he'd find out what the question was, but right now he was sure of the answer.

Forget about secret societies. Forget about time police. Policemen had to have nice logical minds, and to deal with time you needed a mind like Mrs Tachyon.

But there was someone else who'd know where they'd be today, wasn't there ...

Because ... supposing we didn't go back? Supposing ... maybe we went back and did things wrong?

He started to run.

Johnny dodged across the road. A car hooted at him.

Across in the car park, a man in black, with black sunglasses and a peaked black hat, got out of the car and burned into the mall.

Johnny leapt over the low wall into the car park and weaved between shoppers and their trolleys ... ... And panted to a halt in front of the car.

It had stopped right in front of the entrance, where no-one was ever allowed to park.

In the bright sunlight it looked even blacker than Johnny remembered. Its engine ticked occasionally as it cooled down. On the hood was a silver ornament.

It looked very much like a hamburger.

If he squinted, Johnny could just make out a figure in the rear seat, a mere shadow behind the darkness of the glass.

He ran around and snatched at the handle of the back door, yanking it open.

"All right! I know you're in there! Who are you, really?"

Most of the figure was in deep shade, but there were a pair of hands visible, resting on a black cane with a silver tip.

Then the figure moved. It unfolded slowly, and became a large man in a coat that was half coat, half cloak. He emerged carefully, making sure both feet were firmly on the ground before easing the rest of his body out of the car.

He was quite tall, tall enough so that he was big rather than fat. He wore a large black hat and had a short, silvery beard.

He smiled at Johnny, and nodded at the others as they hurried up.

"Who am I?" he said. "Well, now ... why don't you guess? You were always good at this sort of thing."

Johnny looked at him, and then at the car, and then back up the hill to where the old church was just visible.

"I think ... " he said.

"Yes?" said the old man. "Yes? Go on?"

"I think that ... I mean, I don't know ... but I know I'm going to know ... I mean, I think I know why you've come to find us ... "

"Yes?"

Johnny swallowed. "But we were-" he began.

The old man patted him on the shoulder.

"Call me Sir John," he said.

Trousers of Time

There were differences in the mall. One big difference, certainly. The burger bar had changed. There were different shaped paper hats, and the colour scheme was blue and white instead of red and yellow.

The old man led the way.

"Who is he?" hissed Kirsty.

"You'll laugh if I tell you! This is time travel! I'm still trying to work out the rules!"

Sir John sat down heavily in a seat, motioned them to sit down as well, and then did the second-worst thing anyone could do in a fast-food restaurant.

He snapped his fingers at a waitress.

All the staff were watching them anxiously.

"Young lady," said Sir John, wheezing slightly, "these people will have whatever they want. I will have a glass of water. Thank you."

"Yes, Sir John," said the waitress, and hurried away.

"You're not s'posed to do that," said Bigmac hoarsely. "You're s'posed to queue up."

"No, you're supposed to queue up," said Sir John. "I don't have to."

"Have you always been called Sir John?" said Johnny.

The man winked at him.

"You know, don't you," he said. "You've worked it out. You're right. Names are easily changed, especially in wartime. I thought it might be better. I got the knighthood in 1964 for services to making huge amounts of money."

The waitress hurried back with the water, and then produced a notebook and looked expectantly at them all with the bright, brittle smile of someone who is expecting to be sacked at any moment.

"I'll have ... well, I'll have everything," said Yoless.

"Me too," said Bigmac.

"Cheeseburger?" said Johnny.

"Chilli beanburger," said Kirsty. "And I want to know what's going on, okay?"

Sir John beamed at her in a slightly distracting way. Then he nodded at the waitress.

"Make me one with everything," he said, slowly and carefully, as if quoting something he'd heard a long time ago, "because I want to become a Muslim."

"A Buddhist," said Yoless, without thinking. "You always muck up the punchl-" Then his mouth dropped open.

"Do I?" said Wobbler.