'The conversation in the restaurant sounds a bit staged, doesn't it?' she said finally.

'What do you mean?'

'It seems to me it could have been acted out by the Pearsons specifically so that the staff or other diners would hear it, and be able to report later that David's battery was running low. It's far too convenient.'

Cooper nodded, feeling slightly disappointed, though he didn't know why.

Villiers opened the door of the car again.

'I'll do The Stones, then, shall I?' she said.

'We'll both go,' said Cooper.

She watched him lock the car and pull on his jacket, folding the OS map and shoving it into his pocket.

'You want to go all the way up to Hurd Low and check out your theory, don't you?' said Villiers. 'Your speculation?'

Cooper smiled. 'You know me too well.'

They turned the corner by the youth hostel, past the entrance to Peveril Castle, which loomed above them on the hill. They entered The Stones by an outdoor clothing shop and found themselves in a narrow s.p.a.ce between buildings, their footsteps echoing against the walls as they pa.s.sed the tables outside the fish and chip shop. The river and the Peakshole Water bridge were just a few yards further on, where The Stones met Goose Hill.

Cooper tried to imagine that he and Villiers were David and Trisha Pearson leaving the George after their meal. With a bit of effort he could see the whole thing in his mind's eye a the Pearsons looking at the falling sleet as they walked out of the door of the George, pulling up the collars of their coats and setting out to walk in the direction of their holiday cottage.

It had been dark for hours by then, of course. But if the Pearsons had chosen this route via The Stones and Hurd Low, they wouldn't have left the street lamps of the town behind until they were on Goose Hill, just pa.s.sing the last house and the back gates of Goose Hill Hall. He realised they were climbing quite steeply already, as they made their way up the slope of the hill overlooking Cavedale and the gorge of Peak Cavern itself.

He could picture the Pearsons reaching the top and coming out on to this gentler slope near Hurd Low, which had fine views in daylight towards Winnats Pa.s.s and Mam Tor. They must have had torches with them, because they would have been beyond any lights by that time, and the sky was heavily overcast. They would surely have been aiming to follow the path that linked up with the Limestone Way, just over the moor.

But the weather had changed in that time. The light flurries of sleet that had already been falling while they lingered in the George must have become more frequent as they walked up Goose Hill, turning to snow by the time they left the shelter of the town.

Cooper shook his head again. People so often didn't realise how different the weather conditions could be when you gained a few hundred feet in height. Within minutes, the Pearsons could have been struggling through a blizzard blown across the moor by the wind. Their torches would have been almost useless, the track disappearing rapidly under drifting snow.

Was that what they'd done? He wondered if there was a point where they'd considered turning round and going back to Castleton. Or had they simply pressed on, perhaps misjudging the distance to their cottage, which had been such an easy walk in daylight and fine weather? He imagined them laughing and thinking what fun it was to walk through the snow in the darkness, with the mountains of the Dark Peak lurking in the low clouds and the sounds of civilisation deadened by the snowfall. He could see even David Pearson running ahead, kicking up the snow, calling to his wife, perhaps making a s...o...b..ll to throw at her. All a big joke. Just a bit of a laugh.

The amount of alcohol they'd consumed might well have impaired their judgement. Those two bottles of wine could have led them astray from the path. It only needed one rash decision, and they were lost. It was so easy to get disorientated on the moor, to follow a dry-stone wall for rea.s.surance, then cross a stile in the wrong direction. He supposed the Pearsons didn't have a map with them, let alone a compa.s.s. Far too many walkers went on to the hills without any of the proper equipment.

Cooper looked at the OS map again. Those last few hundred yards, where the path south from Goose Hill ran alongside the Limestone Way, were scattered with the ominous symbols indicating disused mine workings.

Villiers had stopped, and he turned to see what she was doing.

'I'm starting to get the idea,' she said, with a hint of surprise in her voice.

'You are?'

'It felt really safe when we walking up past the houses. You're so closed in there, it's as though you're protected. It evens feels a bit claustrophobic, because the buildings are packed so close together.'

'I've often thought that about Castleton,' said Cooper.

'But it's misleading, isn't it? It gives you a false sense of security. Because once you're up here ...'

She gestured towards Mam Tor, the sweep of her arm expressing the sudden wildness of the landscape. It was quite unexpected after the intimacy of Castleton's narrow lanes, even for someone who knew the area well.

Cooper followed her gaze. So when the Pearsons got up on to the moor, what would they do? Were they looking for a light in the distance to guide them? Had they been searching so hard that they hadn't seen the headlights of a car sitting on Goose Hill, where someone had been waiting for them? Were they surrounded by that eerie silence created by snow, the world around them white and dead and hushed? Or had the snow been driving horizontally across the moor, the wind moaning and whining like an animal?

It was funny how in winter everyone found it difficult to remember what summer was like, and in summer it was just as hard to imagine the cold of winter.

Yesterday, surrounded by acres of blackened heather, with smoke still drifting across the slopes, Cooper would have found it almost impossible to picture Oxlow Moor deep in snow. After months of dry, unseasonably warm weather, it took quite a leap of the imagination to visualise the freezing-cold conditions the Pearsons would have been struggling through that night. They must have gone over that same hill he could see now in the distance, but in the teeth of an icy wind and zero visibility.

Cooper recalled driving back from the Light House to Bridge End Farm one winter night many years ago, with horizontal sheets of snow streaming through the headlights of Matt's Land Rover and sweeping across the road. No one lost on the moors in those conditions would have stood a chance, unless they found shelter.

To the north of Oxlow Moor, Winnats Pa.s.s was hardly an easy road to negotiate at the best of times. But once a bit of snow began to settle, and drivers found their wheels failing to get traction on the first incline, they soon turned back and looked for another way out of Castleton. Well, there wasn't another route a not in this direction. The old A625 had been swept away by the landslides off Mam Tor years ago.

So, even if they had any visibility in the snowstorm, the Pearsons would have seen little or no traffic pa.s.sing to the north. No headlights to rea.s.sure them that there were other people around that night.

Where was it the family came from again? Surrey, somewhere just south of London. Dorking, that was it. In their day-to-day lives, they were probably never out of sight or earshot of a major trunk road. They were within spitting distance of the permanently congested M25, almost under the flight paths of two of the busiest airports in the world.

The Peak District wasn't exactly the remote, inaccessible wastes of the Antarctic. But that night, for the Pearsons, it might as well have been.

When Villiers had gone, Cooper looked at his watch. It would be a good time to catch his brother at Bridge End Farm. Matt didn't like being disturbed during milking or when he was out on the tractor. But right now, he'd probably be tinkering in the workshop or the equipment shed.

'Ben? How's it going?' said Matt when he answered. 'Nothing wrong, is there?'

'No, no. Everything's fine.'

'We've not seen you and Liz for a while. We thought you might have called round.'

'Oh, why?'

'Well, aren't there things to discuss? I mean ...'

'Oh, you mean the wedding.'

'Well, yeah.'

'We've been a bit busy, Matt. House-hunting, looking at cakes ... You know the sort of thing.'

Matt sighed. 'Yes, I remember.'

'But you're right, we do need to talk some time.'

'Kate says I can't make any rude jokes during my speech,' said Matt. 'Is that right? I thought it was traditional for the best man.'

'You can say what you like, as far as I'm concerned,' said Ben.

'Good. I'm working on it. There are one or two incidents I remember ...'

'Yes, well ... don't forget how faulty your memory is sometimes.'

'We'll see.'

Ben hesitated, listening to the clang of a spanner in the workshop, picturing Matt carrying on working with one hand while holding his phone with the other.

'How's everything on the farm?' he asked. 'Are things picking up?'

'Well, I'm hoping we might make a bit of money from the wool this year,' said Matt. 'At least a fleece will be worth more than the cost of shearing it, for once.'

'That's good.'

There was a brief silence.

'Well,' said Matt, with a laugh. 'You didn't phone me to talk about the wedding arrangements, and I don't think you're really all that interested in the price of wool. So ...?'

'You're right. It's do to with an inquiry that's come up again.'

'Ah, let me think. According to the news, they're reopening the case of that couple from down south who went missing.'

'That's right. The Pearsons. That's what I wanted to ask you about.'

Matt stopped clanging the spanner. 'Me? What would I know about it? I read the papers and listen to the local news like everyone else, but that's it.'

'That Christmas, around the time the Pearsons disappeared. Do you know when I mean?'

'Yes?'

'There was a party of some kind at the Light House, wasn't there?'

'The Eden Valley Young Farmers Club. It was their Christmas p.i.s.s-up. I mean, celebration.'

'What night would that have been, Matt?'

'Monday, I think. I haven't been a member of the YFC for a good few years now, Ben. I'm too old. They don't want you when you're past twenty-six. We were only there that Christmas as guests. I judged the handling cla.s.ses at the show for them earlier in the year.'

'Yes, I remember,' said Ben uncertainly.

In his mind were fragmentary flashbacks to the evening. A lot of sweating, laughing faces. Music, shouting, perhaps a bit of dancing. Christmas lights had been strung over the doors; a decorated tree stood in one of the windows.

'It was always a good do at the Light House,' said Matt. 'It was held just before they closed the pub for Christmas. There wasn't as much pressure to leave when eleven o'clock came round, if you know what I mean. The YFC lads took it as a challenge to drink the place dry.'

'Yes, of course. I'd forgotten the Light House used to close for Christmas until old Thomas Pilkington mentioned it.'

'The Whartons, who ran it, liked to have Christmas on their own, as a family. I can't fault them for that.'

'No.'

Ben was trying to picture the main bar area. Who had been there? He saw three middle-aged men sitting on a bench discussing the quality of the beer, two young couples laughing at a table full of vodka bottles, an elderly woman on her own in the corner with a gla.s.s of Guinness and a plastic carrier bag. Oh, and a noisy group standing at the bar. Not locals, surely.

'I wonder what happened to the Whartons when they had to leave the pub,' said Matt. 'I never heard.'

'I've no idea,' said Ben. 'I'll have to find out.'

'Anyway, you were quite a hit that night in the Light House.'

'Was I? I usually try to keep a low profile. So many people know that I'm a police officer.'

'n.o.body would have taken too much notice of that, once you started singing.'

'You're kidding.' Ben shook his head. 'I don't remember that.'

'It's no wonder you don't remember.' Matt laughed again. 'You never could hold your drink that well, Ben. You were as p.i.s.sed as a newt that night.'

11.

Samantha Merritt would be in shock later. But Diane Fry knew the early stages could provide valuable information from bereaved relatives, details she might otherwise have to wait days for.

To some, her approach might seem cold and insensitive. Exploitative, even. She could practically hear it being said about her now, though behind her back, of course. But the family of a murder victim wanted the killer found, didn't they? And for that to happen, she needed information about the victim a as much of it as possible 'The funny thing is, Aidan called me and left a message,' said Samantha. 'He said he was on the moor near the fire. It can't have been very long before he, you know ...'

'He was on Oxlow Moor? Near the pub where he was found?'

'Yes, up there somewhere. I just thought he'd gone to watch the fires. A lot of people do that, don't they?'

'Yes, I'm afraid so.'

'It's a funny kind of spectator sport. But Aidan was interested in things like that. He wanted to be at any big event he thought was likely to be in the news. I suppose it made him feel he was seeing history take place.'

Fry studied the room as Mrs Merritt spoke. The house was neat and clean, but otherwise unremarkable. The furniture and decor ranged through beige to off-white. Everything she saw seemed bland, much like the victim's widow herself. Samantha was a plain woman, with straight brown hair that seemed to have become instantly damp with her tears and hung raggedly round her face. She nervously tore tissues in half from a box at her elbow on the sofa.

'What did he say to you when he called you?' asked Fry.

'Well, he was rambling, not making any sense at all. Something about the ninth circle of h.e.l.l.'

'The what?'

'The ninth circle of h.e.l.l.'

'He must have been referring to the fires, I suppose.'

'He could have been,' said Samantha doubtfully. 'It feels so strange, the fact that those were his last words to me. And yet I couldn't understand what he was talking about. I wish he'd left me a different message.'

'I'm sorry.'

Fry was silent for a moment, allowing Samantha Merritt the surge of emotion. It mustn't overwhelm her, though. Not at this stage. Fry still needed her to focus.