They spent the rest of the afternoon concentrating on trying to piece together Michael Clay’s movements since he left his home in Great Barr. If his daughter was telling the truth now, he had set off on Tuesday afternoon, and must have arrived in Derbyshire early in the evening. Did Patrick Rawson’s death prompt the journey? But how could Clay possibly have known about it by then?

A quick phone call established that he hadn’t booked in at the Birch Hall Country Hotel, where Patrick Rawson had stayed. Why was that? Well, maybe Clay was more careful with the company’s money, and had found somewhere less expensive. Perhaps he just wasn’t interested in golf.

That raised the question of Michael Clay’s relationship with Deborah Rawson. Fry thought back to the one occasion she’d seen them together, in the reception area downstairs. Had there been any hint of a closer liaison between them than was suggested on the surface? Could she have read a suggestion in their body language that they were having an affair?

Fry set Beck Hurst and Luke Irvine to phoning other hotels in the area. There were plenty of them, but at least it wasn’t the height of the tourist season in the Peak District, when strangers passing through for a night or two were so common that they might hardly be noticed.

‘And once you’ve covered the hotels, start on the B&Bs,’ she said.

Unlike Patrick Rawson, Clay hadn’t used his credit card everywhere, or his movements would have been traced by now. Here was a man who had learned the lesson about dropping out of sight, then.

Normally, Fry would have had hopes of tracking his movements by his mobile phone. When a mobile phone was turned on, it was constantly transmitting its position to the nearest tower, identifying itself to the network by its electronic serial number. Phone companies were required to keep records to assist criminal investigations. But in a rural area like the Peak District, the region covered by a tower could be pretty large. Another bit of technology that was more useful for catching criminals in a city.

In this case, the disappearance of Patrick Rawson’s phone, and the fact that Clay’s had already been turned off when she’d tried to call him herself that morning, convinced her that she was dealing with someone who was aware of the technology.

‘Have we got anything from the mobile phone company yet?’ she called. ‘When did Clay’s phone log off the network?’

‘Wednesday afternoon, about two thirty. But they say they can’t narrow down the position of the handset better than a radius of a mile or two. And since then he could have gone anywhere, with his phone switched off.’

‘It’s Friday now,’ said Fry. ‘He could have reached Australia since Wednesday afternoon, for heaven’s sake. Erin Lacey has a bit of explaining to do, when I get to speak to her.’

‘I wonder what she thought her father was up to,’ said Murfin.