A boy wearing pyjamas stuck his head round the end of their space.

‘Go to sleep, will you?’ he said. ‘You’re keeping everyone awake.’

‘We heard a noise,’ said Monkey-Boy.

The boy listened. For a while there was silence, then the scraping started up again. The boy made a dismissive grunt.

‘Could be anything,’ he said. ‘There’s always noises here. It’s a really big old building. You get used to it.’

‘Could it be grown-ups?’

‘Even if it was they can’t get in here,’ said the boy. ‘This gallery’s fortified. It was designed to keep the minerals safe. Some of them are really valuable. There’s a bit down the end that’s built like a giant safe. No grown-up could ever get to us. Tomorrow I’ll show you around. You can help us feed the chickens.’

‘I’d like that,’ said Ella. ‘I like chickens.’

Bill smiled to himself. If they had chickens maybe they had chickens in breadcrumbs.

‘Goodnight,’ said the boy. ‘That noise doesn’t mean anything. Just go to sleep.’

‘What’s your name?’ Ella asked.

‘Everyone calls me Wiki.’

‘Goodnight, Wiki. We’re not scared of the noise now …’

Chapter 8

8

Two floors above where the kids were sleeping, in a forgotten room inside the east tower, sat a boy. He wore a black roll-neck jumper and had very pale white skin. He was sitting cross-legged, sharpening a knife against a piece of stonework, the sound travelling through the walls of the building.

Scrape, scrape, scrape …

He’d taken the knife from the girl, Emma, after he’d strangled her down there on the lower level. Her last words had been, ‘Why are you doing this, Paul?’ He’d wanted to explain, but he hadn’t been able to put it into words. All he knew was that he had to let the sickos through. The kids here, they hated him; they’d killed his sister, Olivia. He was sure of it. His memory wasn’t so clear. He thought he must have been ill recently. A fever of some sort. It made you forget things. He wouldn’t forget his sister, not Olivia. Never forget what they’d done to her …

What had they done …?

Had they really killed her?