She shouted to Doreen to bring her a bowl of chips, maybe a burger if they could run to it. When the food arrived she had her eyes shut and was lost in thought – not relaxed at all, but the ideas bouncing around in her brain, random images colliding and connecting and almost making sense. She ate too quickly because she didn’t want to lose the thread of her deliberations and ended up with indigestion that stayed with her all night.

Later she made a call to Durham prison. ‘Yes, I know what time it is. But this is urgent. I need to get a message to Mattie Jones. Even better, let me speak to her.’

But the governor was unsympathetic. He’d been called in on his night off. There’d been a suicide and then trouble on one of the wings. They’d done an early lock-up in the hope of calming things down. He implied that he wouldn’t put the safety of his officers and inmates at risk on the whim of a policewoman. Vera pressed him, but without success. There was surely nothing, he said, patronizing and unmoving, that couldn’t wait until the morning.

As soon as that call was ended, Ashworth rang. Hannah Lister was back home, he said. He didn’t know where she’d spent the afternoon, but he’d seen her arrive. Simon was there too now. Did Vera want him to chat to her?

‘No,’ Vera said. ‘Best leave things be, for tonight.’

For the last time she stood up and halted in front of the fire. There was a temptation to stay where she was, to curl up in the big armchair and sleep the night there. But she went out into the soft, dark evening, intending to drive home.

Halfway there the idea came to her, sudden, like a light bulb flashing above her head in the cartoons she read when she was a child. In comics bought for her by Hector because he loved them too. She did a U-turn the next place she came to and went south and east towards the coast.

Tynemouth was hidden by the misty drizzle and she came on it suddenly, the lamps on the wide main street hardly throwing enough light to park the car. Outside there was a smell of salt and seaweed. The foghorn was sounding, as it had that first time she’d come to interview Morgan.

There were no lights on in his flat. She looked at her watch. Nine o’clock. Too early, surely, for the couple to be in bed. All the same she rang the bell and banged on the door. No answer. Someone appeared in the mist at the top of the street. Tall as Morgan and wearing a long coat, a snug hat that gave the same outline as a bald head would. But it wasn’t him, she saw as he approached. This man was younger, a student.