It seemed to Cooper that traces of pagan legacy were still there to be seen at every turn in this area, though few people noticed. They didn’t see them because their attention was focused on shop windows and traffic, the obsessions of modern society that overlaid history and pushed ancestral beliefs into the background. Now it was as if these ancient objects existed in an extra dimension, where they were only visible if you knew they were there and you looked straight at them.

There was a representation of Sheela-na-Gig incorporated into the stonework of St Helen’s Church at Darley Dale. The goddess of creation and destruction. Few people noticed it, surely, or understood its meaning. If they did, they’d be campaigning for its removal.

A couple of miles down the road, a display cabinet in Matlock church still contained a set of crantsies. Time-darkened maiden’s garlands, each one commemorating the death of an unmarried woman. Their wickerwork frames were decorated with symbols of purity – ribbons, roses, flowers of folded white paper – set around a centrepiece of a collar, a pair of gloves or a handkerchief, something that had belonged to the woman.

‘Is folklore important in Bulgaria, Georgi? I imagine it is.’

‘Yes, certainly. When I was very young, my grandmother gave me a book of Bulgarian fairy tales. The stories had many supernatural characters – werewolves, vampires, wood-nymphs. Lots of pictures. They stay in your mind when you’re a child.’

‘Yes, that’s right.’

‘I remember one fairy tale in particular. It told about a man who finds himself on another earth, in a different world. The only way he can get back to his own world is by riding on the backs of two eagles. But he has to feed the eagles with his own flesh so that they will carry him.’

Fairy tales weren’t really Cooper’s thing. But he knew some of them were supposed to have profound symbolic meanings, if you could manage to figure them out.

‘And what did that story teach you, Georgi?’

‘That sometimes it is necessary to sacrifice everything, in order to get to where you have to be. Even to sacrifice your own flesh and blood.’

‘I see.’

Then Kotsev smiled, his dark eyes glittering. ‘Also, that you should never trust eagles. Even when they say they’re doing you a favour.’

The Shogun had been abandoned under a bridge that was left over from a disused mineral line. It wasn’t even a bridge any more, because the central section had been removed. But it had only crossed a farm track anyway. By the looks of the deep tread on the wheel tracks in the mud, the farmer had probably passed the Shogun several times this week without bothering to report it.