Her biological identity had been established, at least. Now the anthropologist and the forensic artist were passing the responsibility back to him. He had to find out who Jane Raven really was.

Twenty-five miles away, in the centre of Edendale, Sandra Birley had stopped to listen. Were those footsteps she could hear? And if so, how close?

She turned her head slowly. Echoey spaces, oil-stained concrete. A line of pillars, and steel mesh covering the gaps where she might hurl herself into space. A glimpse of light in the window of an office building across the road. But no movement, not on this level.

Sandra clutched her bag closer to her hip and followed the stairs to the next level. At night, multi-storey car parks were the scariest places she knew. During the day, they were made tolerable by the movement of people busy with their shopping bags and pushchairs, fumbling for change, jockeying for spaces amid the rumble of engines and the hot gust of exhaust on their legs. But after they’d gone home, a place like this was soulless and empty. Drained of humanity, even its structure became menacing.

She pushed at the door to Level 8, then held it open for a moment before stepping through, her senses alert. Not for the first time, Sandra wondered whether she ought to have worn shoes with flatter heels, so she could run better. She fumbled her mobile phone out of her bag and held it in her hand, gaining some reassurance from its familiar feel and the faint glow of its screen.

This was a night she hadn’t intended to be late. A last-minute meeting had gone on and on, thanks to endless grandstanding from colleagues who wanted to show off, middle managers who didn’t want to be seen to be the first going home. She’d been trapped for hours. And when it was finally over, the Divisional MD had taken her by the elbow and asked if she had a couple of minutes to go over her report. Why hadn’t he taken the trouble to read it before the meeting? But then, why should he, when he could eat into her personal time, knowing that she wouldn’t say no?

Her blue Skoda was parked at the far end of Level 8. It stood alone, the colour of its paintwork barely visible in the fluorescent lights. As she walked across the concrete, listening to the sound of her own heels, Sandra shivered inside the black jacket she wore for the office. She hated all these ramps and pillars. They were designed for machines, not for humans. The scale of the place was all wrong – the walls too thick, the roof too low, the slopes too steep for walking on. It made her feel like a child who’d wandered into an alien city. The mass of concrete threatened to crush her completely, to swallow her into its depths with a belch of exhaust fumes.

And there they were, the footsteps again.