Cooper was pleased to see that both the former cotton mills in this part of the Wye Valley had been converted into fashionable apartments after years of dereliction. The distance between the two mills was only about three-quarters of a mile, a little more if you followed the loops and weirs of the Wye. Upstream, Litton Mill had been notorious for child exploitation in the nineteenth century, when it was owned by the Needham family. Orphans had been brought from London to work in the mill, and beatings and abuse were rife. In fact, so many children had died that the Needhams sent their bodies to other parishes for burial, to conceal the scale of abuse from the authorities.

Yet Cressbrook had been entirely the opposite, a testament to the enlightenment of a self-educated carpenter. William Newton had built his mill like a grand Georgian mansion, with a village school and rows of pretty lattice-windowed cottages for his workers. But could Newton’s tenants see the blood of his rival’s child apprentices flowing downstream and over the weir? For the sake of residents in the new apartments at Litton Mill, Cooper hoped that the dead slept easy.

There was a hairpin bend above Cressbrook, quite a tricky turning on the way up the steep hill. And a few yards below the bend was the road into Ravensdale. It was tarmacked for part of the way, but only as far as Ravensdale Cottages, the old mill workers’ houses known locally as The Wick. The cottages were tiny, twelve of them in two rows facing each other across a sloping strip of earth. They were built of random limestone, with steps up to the front doors, arched leaded patterns in the windows and Russian vine covering the walls.

The road through Ravensdale was still wet, though the rain had stopped hours ago and the sun was out on the higher slopes. The upper end of the dale was so quiet that Cooper could hear the voices of two rock climbers calling instructions to each other as they clung to the face of Ravenscliffe Crag.

Beyond the cottages, a muddy footpath wound its way further north, heading up into Cressbrook Dale as far as Peter’s Stone, and over to Wardlow. But on the right a track forked off through the fields and followed the stream. Last year’s leaf litter lay in decomposing heaps at the sides of the track, churned into brown sludge by the wheels of passing vehicles.

A group of walkers went by, rustling in their cagoules and waterproof leggings, their boots crunching on the damp stones and splashing in the puddles. All four had their heads down, watching their feet. There was no talking on this stretch. Perhaps they were saving their breath for the climb up the other side of the dale, where the path would be muddy and dangerous.