To his immense relief, it was Fry who broke the silence. She seemed to have two distinct halves to her brain, the way she could switch from one to the other so easily. But there was no doubt about it, thought Cooper – the professional part of her brain was the one that assumed dominance most easily.

‘Lies,’ she said again, and took a long breath, as if inhaling the fumes from her wine. ‘You know, the first person to deceive us in the Rawson enquiry was the manager at Le Chien Noir,’ she said.

‘How is that?’ said Cooper, eager to encourage this time.

‘He was so vague about the man that Patrick Rawson was having dinner with that Monday night. He couldn’t give a completely misleading description, in case we asked anyone else and their version contradicted his. So he was deliberately vague. He knew perfectly well who the other man was – Maurice Gains, Rawson’s partner in R & G Enterprises.’

‘Oh. They were trying to find restaurants to serve their horse meat, weren’t they?’

‘Of course,’ said Fry. She took another long gulp of her drink. ‘But they already had wind of the trichinosis outbreak. The restaurant must have been desperate to avoid any suggestion they were serving horse meat. Reputation is everything in that business. Neil Connelly was already trying to distance Le Chien Noir from the bad publicity.’

‘What are you going to do?’

‘Suggest that Environmental Health pay a visit to Le Chien Noir.’

Cooper noticed that she was having a bit of difficulty saying the name of the restaurant. The third time it had definitely come out wrong.

‘Diane, are you all right?’

‘Why does everyone keep asking me if I’m all right?’

‘Well . . . I don’t know why everyone else does,’ said Cooper. ‘But I just noticed you seemed to be drinking quite fast. For a lunchtime, anyway. I didn’t know you were a day-time drinker.’

‘I’m not.’

‘OK.’

‘Except in exceptional circumstances.’

Cooper laughed uneasily. ‘You almost managed to say that without slurring.’

‘I don’t slur. I’ve never slurred in my life. I’m a positively slur-free zone.’

Overwhelmed with relief that the moment had passed, Cooper began to feel giddy with the idea that had come into his head.

‘You know what?’ he said. ‘I think we should go for a walk. A bit of fresh air will do us good. Did you bring your boots?’

‘It’s raining,’ protested Fry.

‘No, it’s stopped. It’s nice and fresh out there.’

Chapter Thirty-eight

THEY CROSSED THE road at Middleton Dale, then walked up through the Tarmac site at Darlton Quarry, its sides terraced like a huge amphitheatre. Excavators were loading dumper trucks in the bottom of the quarry. A hydraulic drill probed at the rubble, splitting the larger stones. Nearer by, a giant shovel sculpted the edges of the worked-out areas.