Then Cooper sniffed. ‘What would you say that smell is, Wayne?’ he asked.

Abbott began sniffing too. ‘It’s petrol, I think.’

‘Have there been any vehicles down here?’

‘Not recently. The tyre marks would be clear enough in the mud. We can only make out a few mountain bikes, that’s all.’

‘Strange. It’s a pretty strong odour.’

Abbott nodded. ‘We’ll see if we can identify any traces from the soil and vegetation close to the body, shall we?’

‘That would be great.’

Pilsbury Castle had occupied an area of high ground overlooking the River Dove. The Normans had built it to re-establish control of the area after William the Conqueror’s campaign to devastate and subdue the north of England. In medieval times the site would have overlooked a key crossing point of the river.

Cooper looked out over the valley of the Dove towards the peculiar shapes of Parkhouse Hill and Chrome Hill in the distance to the north. He would be able to see the Corpse Bridge from here, if it wasn’t for the trees around it. He could certainly make out Knowle Abbey quite clearly. And across a stretch of parkland, located at a suitable distance from the abbey, he could see the village of Bowden.

24

Once the photographs had been taken and the scene thoroughly examined, the safe retrieval of the body from its position at the foot of the outcrop was going to be difficult. The slope was close to being perpendicular.

Ben Cooper walked round the outer circumference of the castle site. Of course, the steep slope and the limestone knoll had been part of the natural defences for the site. The castle itself was either destroyed after its owners took the wrong side in a twelfth-century rebellion or it may simply have become redundant as the village of Pilsbury became increasingly depopulated. Its timber defences were long gone, anyway. Now there was little to see except for the mounds, and the remains of ditches and earthworks.

From the Pilsbury side of the river, he had a good view of a steep descent on the opposite side of the valley. The green lane that snaked down towards the Dove was called Marty Lane, but was still known locally as ‘the old salt way’. From here it headed up on to the limestone plateau, then over the Derbyshire hills towards the towns of Monyash and Bakewell, and onwards to Chesterfield.

When he’d done a complete circuit, he found Luke Irvine waiting for him.

‘Ben, uniforms have been calling on the houses in Pilsbury,’ said Irvine. ‘It didn’t take them long.’

‘And?’

‘Well, we’ve got some witnesses.’

Cooper turned to Irvine with automatic interest, then stopped himself.

‘Shouldn’t you be telling DS Fry this?’ he said.

‘She’s not here,’ pointed out Irvine.

‘Fair enough.’

‘They’re just down in Pilsbury.’

‘Okay, we’ll go and talk to them.’

‘By the way, I was thinking about the Sandra Blair case,’ said Irvine. ‘Last night in the pub.’

‘Is that what you spend your time doing when you’re in the pub?’ asked Cooper.

‘Not usually.’

‘I’m glad to hear it.’

Irvine explained to Cooper his idea based on the Agatha Christie plot.

‘A conspiracy?’ said Cooper. ‘More than one perpetrator involved?’

‘I know it sounds crazy,’ began Irvine.

‘No, it’s interesting that you thought of it too,’ said Cooper.

‘Really?’

‘A conspiracy? Maybe. Let’s hope so, anyway.’

‘Why, Ben?’

‘Well, every conspiracy needs a network,’ said Cooper. ‘And every network has a weak link.’

It seemed that a party of late-season tourists had been renting a six-bedroom property on the Derbyshire bank of the Dove, an imposing three-storey Georgian house that used to be part of the Knowle estate. When Cooper saw it, he knew it must originally have been the home of someone significant – the estate manager at least, or perhaps an elderly relative of the earl, who had to be given a place to live on the estate but wasn’t wanted too close to hand. Premium rental properties came at a high price in the Peak District, even in November. This house probably cost around two thousand pounds a week to rent.

‘So what’s their story?’ asked Cooper as he and Irvine headed down the few yards of track to the hamlet of Pilsbury.

‘Some people called Everett rented the property for a birthday celebration and invited three other couples to join them,’ said Irvine. ‘They’re all friends from the Manchester area. Young professionals, you know the type. Too much money to spend on indulging themselves.’

‘I’ve heard of the type,’ said Cooper.

‘Well, according to local residents, they’ve been behaving oddly ever since they arrived. They’ve been wandering around at night in the dark. People have reported hearing raised voices, right through into the early hours of the morning. This is a quiet area, as you can see.’

‘That’s an understatement.’

Raised voices in the early hours of the morning was normal for the centre of a town like Edendale. But not out here, with only three or four houses and a couple of farms, and a road that nobody ever used on the way to somewhere else.

‘Let’s go and speak to them,’ said Cooper.

Pilsbury was what they called a shrunken village. Though it claimed to date back to Anglo-Saxon times and appeared in the Domesday Book, the few present-day houses were late-seventeenth or early-eighteenth century. It might have been a busy little spot in past centuries, he supposed. The castle was built to defend a river crossing that had been an important trade route through Pilsbury. But the centuries had passed it by and history had abandoned it. There were other settlements like this scattered around the landscape, some marked only by the bases for houses and garden plots enclosed by half-defined bankings, buried among hawthorn bushes and limestone outcrops.

There was no answer to the door at the elegant three-storey house in Pilsbury. Cooper peered through the front windows, while Irvine walked round the back and checked the garage.

‘It doesn’t look occupied,’ said Cooper.

‘And there are no vehicles. According to what we were told, there should be three cars.’

A farmer passing in a Ford Ranger stopped when he saw them.

‘They’re gone,’ he called. ‘Buggered off. Done a bunk.’

‘When?’

‘Just now. I saw the last bloke going down the road here in his Merc thirty seconds ago.’

‘A Mercedes?’ asked Cooper.

‘Yes, a green Merc.’

‘Do you mean they’ve taken the Hartington road, sir?’

‘Yes, but if you hurry—’

Cooper laughed.

‘Oh, don’t worry,’ he said. ‘He won’t get far.’

The farmer laughed too. ‘Aye, daft sod. He left the first gate open. He couldn’t stop long enough to close it behind him, I suppose.’

Cooper knew this stretch of road. Wallpit Lane was a gated single-track road between Pilsbury and Hartington, skirting the eastern bank of the Dove. He recalled there were perhaps five or six iron gates across it between here and Hartington, the first of them right here by Pilsbury Farm, which had now been left standing open.

‘Why did they run, do you think?’ asked Irvine as they passed through the first gate.

‘Presumably they saw all the police activity,’ said Cooper.

‘Guilty consciences?’

‘Yep.’

‘Shall I call it in? We can get units to intercept him in Hartington?’

‘No need. Ten to one we catch up with him before that.’

‘If you say so, Ben.’

‘Well, look – it’s a gated road. I don’t suppose they’re used to them in Manchester.’

Like so many arrangements in the Peak District, the method of closing these gates was a bit random. Some used short lengths of rusted metal bent into a hook to catch the upper bars of the gate. Others relied on a loop of rope to go over the top of the post. One or two were hung so that their own weight kept them open. The rest had to be wedged just right against a strategically placed lump of limestone. You didn’t get to make a quick getaway on this road.