Not trusting her legs – they’d been through too great a disappointment to act reliably – Elspeth crawled to the corner behind the couch and dug her fingers behind the carpet, pulling on strands where it wasn’t completely tacked down. It took an effort, but the carpet was becoming threadbare and hadn’t been renewed in years. The tacks had little body left to hold on to. Her fingernails screamed at her, but she would not relinquish her grip. Her heart was thumping like a drum. Only that wasn’t right. It was Meggy, hitting and kicking the door. The girl had finally lost it. She was bound to sooner or later. Elspeth realised she’d been much too calm. Now the dam was bursting.

‘Hey,’ she said, releasing the edge of the carpet. She walked over and pulled the screeching girl away from the door. ‘Hey, honey, we have to try something else, that’s all. It’s not over. But you can’t carry on making that much noise, all right? He’ll hear you.’

She cradled Meggy’s head against her chest and rocked her for a minute. When the girl looked up, Elspeth smoothed down her hair and kissed her forehead.

‘Do you know what a plenum is, Meggy?’

The girl shook her head.

‘Neither do I, not really, but we were having some work done to our house, and they had to leave a space a certain depth between the floors. It has wooden joists, the long beams, and some smaller cross-beams, maybe insulation, something to attach the plasterboard to, that makes up the ceilings we see. But there are some weak points. Some gaps. So when too much water spills from your bath, and the ceiling collapses, it’s because the water has found the gaps and run through. We need to find the weak points, okay? Look at the state of that ceiling.’ She pointed at the dislodged lamp. ‘If we can’t go out through the door, and there are no windows, then we have to find another exit, even if that means making one. I need you to help me, Meggy. Can you do that?’

The girl nodded and wiped her cheeks. ‘Sure,’ she sniffed. ‘I can help.’

‘Okay, just one minute.’ Elspeth disappeared into the kitchen and returned carrying a packet of biscuits and a glass of milk. ‘He left some supplies. You haven’t eaten anything since you got up. That won’t help us. You’ll start feeling ill and panicky. Here.’

Meggy did as she was told, chewing biscuits that felt like building rubble in her mouth. She couldn’t taste anything but disappointment. She’d been so sure she’d done it. She’d wanted to rescue Elspeth, to be the heroine. And to beat him. That more than anything else.

Elspeth took the empty glass from Meggy’s hand and set it down, leading Meggy to the spot in the corner behind the sofa.