‘There must be a way of getting the main warehouse doors open from the inside,’ said Einstein. ‘For when lorries made deliveries or picked stuff up. There must be some proper warehouse doors.’

Blue started walking and the others fell in behind him, still keeping bunched up, the torch beams probing ahead. They didn’t have to go far before the corridor widened out into a storage area with rows of metal shelving stacked with packing materials: flat-pack cardboard boxes, empty plastic crates, rolls of bubble wrap and plastic binding material. Rolls of sticker labels.

Blue shone his torch into every corner and under every shelf.

Nothing.

‘What would a grown-up want to be hiding out down here for?’ said Achilleus. ‘They can’t get in and out, there’s nothing to eat. Unless they wanted to send some parcels to their aunties they wouldn’t have no interest in all this junk.’

‘They make their nests underground,’ said Blue.

‘I know it,’ said Achilleus. ‘This just don’t feel like the sort of place they’d choose.’

‘What about all those sickos outside?’ said Jackson. ‘What were they trying to get in for? What were they after?’

‘They only ever after but one thing,’ said Achilleus. ‘Fresh meat.’

‘You think there might be kids down here?’

‘No way. We’d have seen some signs.’

‘Yeah, well, let’s push on,’ said Blue.

The door out of the storeroom through into the next part of the warehouse complex was also unlocked. It led to a short corridor that ran a little way then turned a corner. Its walls were bare concrete. Bundles of cable and bits of pipework ran along either side and there were various shelves and cabinets spaced out along its length. The further they went into the building the plainer it was and the more nervous the kids became. There was no joking now. No talking.

Halfway to the bend they heard a noise. A shuffling, rustling sound. It went as quickly as it came.

They all froze.

‘What was that?’ said Emily.

‘We don’t know, Emily, OK?’ said Jackson, trying not to lose her cool. ‘How could we know? It came from round the corner. We’ve never been here before. So just shut up and listen.’

‘Does someone want to go and take a look then?’ said Einstein.

Jackson stepped forward. Said nothing. Just carried on walking slowly towards the corner where the corridor turned.

Well, this was dumb. Weirdo Jackson. Showing off again. Doing something stupid and dangerous to impress the boys. Only this time she had no idea what she was getting into. For the first time today she was actually scared. She heard a scuff behind her and turned round to find Achilleus catching up with her.

‘Can’t let you have all the fun,’ he said.

‘Thanks,’ said Jackson. And she meant it. She was marginally less frightened now.