‘No, we couldn’t have got here any quicker. It was a washout, after all. We should have called it off when you said, Ben.’

Cooper could hear the disappointment in her tone. Fry had been so sure that Elder was going to provide an important link that would hand her a breakthrough in this enquiry. He struggled to find something to say that would be supportive without provoking her to bite his head off. But he failed.

‘Oh, well. Back the way we came then, Diane?’

‘I suppose so. But we can use the torches now.’

As they walked back towards the invisible machinery and winding house, Fry began to curse. Maybe she found the fog liberating, felt freed by the fact that she couldn’t hear or see anyone. Cooper was trailing behind her, watching his step.

‘What a disaster,’ she said. ‘It’s one bloody disaster after another. Why am I wasting my life here?’

‘It isn’t that bad, Diane. Life can be fun, too.’

‘Fun? I’m nearly thirty years old, and I haven’t had sex for months.’

Cooper didn’t know what to say. He was gob-smacked – and not just in a surprised way, but in the way that felt as though his brain had shut down completely and he had no control over his vocal cords. His mouth fell open, and his eyes flickered nervously until they settled on a suggestion of movement behind the winding gear. But it was only a corner of the engine house, momentarily revealed through a gap in the fog.

‘Mmm, tumbleweed,’ said Fry.

Cooper cleared his throat. ‘Nearly thirty. Does that mean it’s your birthday soon?’

‘Next week.’ Fry sighed. ‘Yes, Christmas. I must have been some kind of miracle baby.’

Cooper became aware that the banging of corrugated-iron sheets had stopped. That could only mean the wind had dropped. He stopped and looked across the mine to the east. He couldn’t see the agent’s house now, or the base of the chimney, and certainly not the scaffold-like horse gin marking the site of the Red Soil shaft. The bank of fog was too dense.

‘Diane, have you noticed the banging has stopped?’ he said.

‘Yes, thank God.’

‘Didn’t it occur to you that there shouldn’t have been any banging in the first place?’ said Cooper. ‘There’s no wind.’

Fry looked at the thick blanket of fog enveloping the mine. ‘No, it didn’t occur to me. But you’re right.’

‘Damn it, I should have noticed before. Damn it.’