Kirsty sat upright. Her breathing was heavy and quick. She threw the quilt aside and jumped out of bed, flicking the light on, looking around the room wildly. She ran out of the bedroom and into the nursery. Jamie got out of bed and followed her. It was freezing in the flat but he barely noticed. He could still hear the baby. What the hell was going on?

Kirsty was standing in the nursery (spare bedroom, spare bedroom – that’s all it is, Jamie reminded himself, until he could persuade Kirsty to try again) staring into the empty cot. Above the cot, a mobile rotated. Farmyard animals – a pig, a chicken, a cow – spun slowly left then right, then left again. The room was lit by moonlight, and the animals cast lifesized shadows on the walls. Jamie switched on the light.

Kirsty turned to look at him. ‘Jamie, can you hear it too?’

‘Yes.’

She clamped her hands over her ears. ‘I thought it was in my head. But you can hear it too? You promise?’

‘ I promise. Come on, let’s get out of here.’ He took her hand and led her back to the bedroom.

The baby’s cries were so clear. Short bursts of treble-heavy crying, followed by long wails that seemed to get louder and louder before suddenly falling silent. For ten seconds, the crying stopped altogether, and Jamie and Kirsty stood in their bedroom, clutching each other, just the sound of their chests beating in the darkness. Then it started again, even louder than before.

Kirsty fell onto her hands and knees. ‘It’s coming from downstairs.’

Jamie had known that already. Had known the moment this started.

‘They’ve got a baby down there,’ Kirsty said in a hushed tone, her eyes wide. ‘Jamie, they’ve got a baby – Lucy and Chris – they’ve got a baby.’

Jamie knelt beside her, leant forward and put his ear to the floor. He tried to think: how long was it since he had seen Lucy? Had she had a bump? Could she have been pregnant?

No – it didn’t make sense.

‘It’s a recording,’ he said. ‘That’s what it is. It’s a fucking recording.’

‘No!’ Even now, after all this time, Kirsty acted as if she was shocked by the lengths Lucy and Chris would go to. She pummelled the carpet with her fists, weak blows which would have been barely audible downstairs, especially over the cries of the baby. She punched and punched, until she collapsed on her front and lay still.

The recording stopped. Halfway through a cry of distress, the baby was hushed. Jamie pressed his ear to the floor again. His whole body was tense, like a spring, waiting for the crying to begin again.