Fry shrugged, but the DCI wasn’t waiting for an answer. He looked around to see who else he could find. ‘You lot, there! Anyone seen these stones before? They’re a famous landmark, they tell me. A significant part of our ancient heritage. They’re an attraction. Visitors flock to see them. What about you?’

The officers shook their heads. They were the sort of men who spent their free time in the pub or in front of the telly, doing a bit of DIY or visiting the garden centre. The ones with kids went to Alton Towers and Gulliver’s Kingdom. But this thing in front of them wasn’t a theme park. There were no white-knuckle rides or ice-cream vans. Tailby turned back to Hitchens.

‘OK, see? We know nothing about it. We’re all as ignorant as a lot of monkeys. This stone circle might as well be a Tibetan yak compound, for all we know about the place.’

‘Yes, but –’

‘Just see that it’s done,’ snarled Tailby.

Then the DCI looked back to where Mrs Van Doon was working. Fry could see that more inscriptions had been scratched into the dirt in the centre of the circle, close to the body. The letters were big and bold, and they spelled out ‘STRIDE’. Whoever had made these was less interested in leaving a long-term record of his presence, though. The drizzle was hardly touching the marks, but a couple of heavy showers would wash them clean away.

‘What about those, then?’ said Tailby. ‘You’re not going to tell me those have been there for years?’

‘No,’ admitted Hitchens. ‘They’ve got to be more recent.’

‘When did it rain in this area last? Properly, I mean?’

Tailby stared around him. The officers gathered nearby looked at each other, then up at the sky. Fry sympathized. They were detectives – they spent all their time buried in paperwork or making phone calls in windowless offices; occasionally they drove around in a car, shuttling from pub to crown court and back again. How were they supposed to know when it had rained?

It was well known that DI Hitchens had just bought a new house in Chesterfield. Tailby himself had a ranch-style bungalow in a desirable part of Dronfield. Most of the other officers lived miles away, down in the lower valleys and the dormitory villages. Some of them were from the suburbs of Derby. It could be blowing a blizzard up here on the moor, piling up six-foot drifts of virgin snow, and all these men would see was a faint bit of sleet in the condensation on their kitchen windows.

‘Does it matter?’ said Hitchens.

Tailby smiled like a fox with a rabbit. ‘It matters, Inspector, because we can’t say whether the inscriptions were written in the last twenty-four hours or the last two weeks.’

‘I suppose so, sir.’