Mrs Tachyon stood and watched them owlishly as they walked, very cautiously, towards her.

The soldier saw a wizened little woman wearing what looked like a party dress with layers of other clothes on top, and a woolly hat with a bobble on it. She was pushing a wire cart on wheels. It had a metal label on it.

‘Tes-co,’ he said. ‘What’s that?’

‘Dunno where she gets half her stuff,’ muttered the sergeant.

The trolley seemed to be full of black bags. But there were other things, which glittered in the moonlight.

‘I know where she got that stuff,’ muttered the soldier. ‘That’s been pinched from the pickle factory!’

‘Oh, half the town was in there this morning,’ said the sergeant. ‘A few jars of gherkins won’t hurt.’

‘Yeah, but you can’t have this sort of thing. ‘Ere, you! Missus! You just let me have a look at—’

He reached towards the trolley.

Some sort of demon, all teeth and glowing eyes, erupted from it and clawed the skin off the back of his hand.

‘Blast! ’Ere, help me get hold of—’

But the sergeant had backed away. ‘That’s Guilty, that is,’ he said. ‘I should come away if I was you!’

Mrs Tachyon cackled.

‘Thunderbirds Are Go!’ she chortled. ‘Wot, no bananas? That’s what you think, my old dollypot!’

She hauled the trolley round and trotted off, dragging it behind her.

‘Hey, don’t go in there—’ the soldier shouted.

The old woman hauled the trolley over a pile of bricks. A piece of wall collapsed behind her.

The last brick hit something far below, which went boink.

The soldier and the policeman froze in mid-run.

The moon went behind a cloud again.

In the darkness, there was a ticking sound. It was far off, and a bit muffled, but in that pool of silence both men heard it all the way up their spines.

The sergeant’s foot, which had been in the air, came down slowly.

‘How long’ve you got if it starts to tick?’ he whispered.

There was no one there. The soldier was accelerating away.

The policeman ran after him and was halfway up the ruins of Paradise Street before the world behind him suddenly became full of excitement.

It was nine o’clock in the evening, in Blackbury High Street.

In the window of the electrical shop, nine TVs showed the same picture. Nine televisions projected their flickering screens at the empty air.

A newspaper blew along the deserted pavement until it wrapped around the stalks in an ornamental flowerbed. The wind caught an empty lager can and bowled it across the pavement until it hit a drain.

The High Street was what Blackbury District Council called a Pedestrian Precinct and Amenity Area, although no one was quite sure what the amenities were, or even what an amenity was. Perhaps it was the benches, cunningly designed so that people wouldn’t sit on them for too long and make the place untidy. Or maybe it was the flowerbeds, which sprouted a regular crop of the hardy perennial Crisp Packet. It couldn’t have been the ornamental trees. They’d looked quite big and leafy on the original drawings a few years ago, but what with cutbacks and one thing and another, no one had actually got around to planting any.