Mark thought for a moment of the woman on Ringham Moor. Her death had at least been sudden; she had been given no time to consider, no time to reflect on what she had done with her life, for good or evil.

Owen had told Mark there were times when it was best to back off, to avoid confrontation, to let something go. He said that a soft word was better than an angry reaction, that a cool head was better than that hot surge of blind rage that was inevitably followed by the realization that you had made a terrible mistake.

Mark passed another stone. It was furred dark green with lichen, so he knew it had come from the north face of the wall. When a wall had been built by Owen, it was solid and reliable, the absolute symbol of stability.

Mark decided he would have to ask Owen again tomorrow about why he hadn’t been able to get hold of him on the radio. And maybe he would ask the day after, too. Just to hear a little bit more reassurance.

The Westons sat together, their faces no longer hopeful. They were losing faith in the investigation, disappointed by their first real contact with the police, dismayed by the realization of their fallibility. And they had noticed that at first they had been talking to a detective chief inspector, then an inspector; now it was a mere acting detective sergeant. The word ‘acting’ seemed to be the biggest insult of all.

‘Don’t take it the wrong way,’ said Eric Weston. ‘We’re sure you’re doing your best.’

‘There are a lot of people working on this enquiry,’ said Diane Fry patiently. ‘There are lots of leads to be followed up. This is just one of them.’

‘We understand. Really.’

Mrs Weston had set out teacups on a glass-topped table. She served the tea as a well-rehearsed routine, performed without any hint of welcome. In the same way, she had apologized for the condition of the lounge, explaining that they weren’t bothering to decorate in view of their move, before long, to the retirement cottage at Ashford. New people always redecorated when they bought a house, she said. So why bother? It would only be wasted expense.

The log basket on the hearth was filled with paper and small sticks, ready to light a fire. A storage heater under the bay window was enough to take the chill off the room. But the decor looked perfectly presentable to Fry. Anything that wasn’t stained by mould or hung with cobwebs looked fine to her. Back at the flat, anything that didn’t have a layer of dust was meant for sitting on.

‘I believe you’ve already been asked about a young woman called Ros Daniels.’