Fry shook her head. 'I still can't see any signs that anything has been taken.'

'There was definitely a vehicle here, though. The fire crews saw it. A white pickup. Just the sort of vehicle you'd use for sc.r.a.p.'

'Probably a white pickup.'

'There were too many people up here. Too many for it to be just a coincidence. Too many for there to be a logical explanation. Not an innocent logical explanation anyway.'

From Fry's research when she first transferred here from the West Midlands, she knew about the ten unsolved murders in Derbyshire Constabulary's history. The oldest went back to 1966, the case of a Chesterfield teenager found beaten to death in a disused factory. It was senseless killings like that that tended to be the most difficult to detect and the most unlikely to result in a successful prosecution.

But whatever had happened inside this pub, it wasn't senseless. At least two people had come together here, if only for a short while. There had been a reason for the killing.

Murder, or the idea of murder, wasn't all that unfamiliar a concept to a lot of people, most of them ordinary, law-abiding citizens. It had been a part of human experience since Cain killed Abel. Normally it all went wrong with the disposal of the body. The killing itself was easy. It didn't take much thought a a red mist in front of the eyes, a violent swing of the arm, and it was done. But a corpse on the floor was a different matter. There were bloodstains on the walls, one of your hairs on their clothes, a fragment of your skin caught under their fingernails. And perhaps a witness who had seen both of you arrive but only one of you leave. From that point, it took a lot of thought. And who was thinking straight in those circ.u.mstances? Most people just panicked and ran.

They'd interviewed some of the firefighters, and a couple of rangers who'd been in the vicinity. But the interviews had produced little of any use. Understandably, their attention had been on the fires, not on the pub. And that was a shame. Given the location, they were the only potential witnesses available.

'The last landlord, you said?'

'Mad Maurice,' repeated Murfin. 'Moved back down into Edendale with his family when the pub closed. Name of Wharton.'

'Why do they call him Mad Maurice?' asked Fry.

'Because he used to get mad a lot,' said Murfin. 'There were loads of things he couldn't stand. Mobile phones, children, people who just came into the pub to use the loo or ask directions. Anything like that, he'd get mad about. Maurice became a tourist attraction in his own right.'

'How do you mean?'

'Well, folk used to come in the pub just in the hopes of seeing him get mad. They thought it was funny. "Let's go and see Mad Maurice," they'd say. Where other landlords called the traditional "Time gentlemen, please", Maurice's shout was "Come on, you b.u.g.g.e.rs, clear off. Haven't you got homes to go to?"'

'Charming.'

'It was just his way.'

'If he shouted that at me, I'd never go back there again.'

'Well that's the point. If you couldn't put up with a bit of abuse, he didn't want you in his pub anyway. It meant you were the wrong sort of customer.'

'Good grief. It's no wonder the place went bust, if he chased away all his custom like that.'

'On the contrary, it was one of the pub's unique selling points. People used to go there because of Maurice. It's a bit like customers going to Gordon Ramsay's restaurant hoping to hear him say the F-word. You know what I mean.'

'Gordon Ramsay is a celebrity chef who's always on the telly. He's famous.'

'Well so was Mad Maurice, in his own way. He was a local celebrity. For every customer he banned from the pub for a using a mobile phone or talking too loud, he'd get ten more coming in to see him do it.'

'A clever marketing ploy on his part, then.'

'No,' said Murfin. 'He just got mad a lot.'

Hurst took a call, and turned immediately to Fry.

'We got an ID,' she said. 'Name of Aidan Merritt, a thirty-five-year-old teacher from Edendale.'

'A teacher? What was he up to at the Light House?'

'Dunno. But here's the interesting thing. His name came up in HOLMES in connection with the Pearson inquiry.'

10.

Ben Cooper parked his Toyota by the little green in the centre of Castleton and opened his Ordnance Survey map. It was a well-used, heavily creased copy of Outdoor Leisure 1, the Dark Peak.

As usual, the area he wanted went off the edge of the map and crossed into the White Peak. That was just to make things more difficult.

Above the town, a team of officers were attempting to follow the route that the Pearsons might have taken from Castleton on the night they disappeared. It had been done before, but DCI Mackenzie had insisted on it being done again. The scope of the search had been widened, taking in a broad sweep of the moor right over to Speedwell Cavern and Winnats Pa.s.s on one side, and including the Limestone Way itself on the other.

In most parts of the country it would be impossible to imagine how two people could simply disappear in open countryside like this. But Cooper was aware of what lay underneath his feet. The whole of this landscape was hollow. It was one huge lump of porous limestone, scooped out over millennia by running water to form endless caves and tunnels and pa.s.sages.

The Peak Cavern system alone ran for more than ten miles before it emerged at Speedwell, and it included the deepest shaft in the UK, twice the size of St Paul's Cathedral. Rain falling on the surface in Cavedale found its way through to the show caverns below and fell as lime-stained waterfalls on the heads of tourists.

Even Sir Arthur Conan Doyle had once said: 'All this county is hollow. Could you strike it with some gigantic hammer it would boom like a drum.' In that wider context, it was far too easy to imagine anything disappearing.

Cooper glanced out of the car window. Up Castle Street, he could see the sign outside the George, directly opposite the parish church. He dialled Carol Villiers' mobile number, and she answered after three or four rings.

'Where are you, Carol?'

'Still at the George.'

'Anything?'

'No. The story stays the same, right down to the details. Except the details are becoming a bit vague by now. I've been going through the names of the other people who were eating here that night. I know it's been done before ...'

'Hasn't it all?' said Cooper.

'Well ... anyway, they're all in the clear. No connection with the Pearsons, so far as I can tell. One couple were from Suss.e.x, which I suppose is not a million miles from where the Pearsons lived.'

'Did they speak to each other?'

'Not that we know of. Not that anyone saw.'

'A washout, then.'

'Of course, we don't have all the names,' said Villiers. 'Some of the customers are unaccounted for. So there are gaps.'

Cooper sighed. 'I know. Thanks, Carol.'

'I'm leaving the George in a few minutes. I'm going to go past the Green.'

'Fine.'

Details of the Pearsons' movements towards the end of that night were sketchy, and had to be partly speculation. What was known for certain was that they'd arrived at the George, where they'd booked a table for dinner at seven thirty. Since their Range Rover III was still standing outside The Old Dairy next day, the presumption was that they'd walked to Castleton. The owner of the cottage confirmed they were keen walkers a that was why they came to the Peak District, they'd said. At the George, staff who'd served them remembered that they'd come in wearing outdoor clothes and walking shoes. It wasn't at all unusual; Castleton was a centre for walkers at any time of the year.

Cooper thought about the photographs of the Pearsons again. You couldn't always tell the outdoor types, of course. And the Peak District had enough variety to attract anyone. But personally, he wouldn't have pegged David Pearson as the kind of man to be hiking over the moors in the middle of winter. The activity had its attractions, without a doubt, but it was minority appeal. Most people would have jumped into the car and driven to Castleton. Almost everyone, in fact, even if they hadn't bothered to check the local weather forecasts. It was one of the factors that had fuelled theories that the Pearsons had set the whole thing up. If you looked at it that way, it was the unlikeliest element of the scenario. Yet from the evidence, that seemed undoubtedly to be what had happened.

Okay, so the meal had gone off uneventfully. The mushrooms in peppercorn sauce, the Bantry Bay mussels, the honey-glazed ham shank. The Pearsons' table hadn't been close to the windows, so they might not have noticed the weather deteriorating. It was only a bit of sporadic sleet anyway. A few wintry showers. What was that to a couple of determined, experienced walkers with the right gear?

But wait a minute. Exactly how experienced were the Pearsons? Cooper made a note to find out. The original inquiry had traced their movements the day before their visit to Castleton, but those had all been by car, surely? They'd filled up the Range Rover at Sickleholme service station, so they must have been using fuel. A trip into Buxton for the Christmas market, maybe. Afternoon tea at the Old Hall Hotel. The Twelve Days of Christmas at Chatsworth House. That would have been David and Trisha's style, if he wasn't mistaken.

But still, they seemed to have decided to walk to Castleton a a distance of about three miles from the cottage. He estimated an hour at a brisk pace. No one could say exactly when they'd set off, so the couple might have taken their time, a leisurely stroll over the moor to work up an appet.i.te, with a nice meal awaiting them at the end of it.

Well, not quite the end of it. There had been the hike back to The Old Dairy to take into consideration.

So what about when the meal was over? When they left the George, the Pearsons were believed to have walked in this direction, past the green and into Bargate, where they could turn directly on to the start of the Limestone Way as they headed back to their cottage.

He watched Villiers do it now, walking up Castle Street, pa.s.sing his car and stopping at the gift shop by the green.

And that was what bothered Cooper. From the statements taken at the time, there was really no confirmation of it a only a pa.s.sing reference to the Limestone Way in the course of conversation with staff at the George.

What if the Pearsons had instead turned the corner of Castle Street by the youth hostel on to the narrow lane called The Stones? Extensive interviews and appeals to the public had resulted in an identification earlier in the evening by customers who had been waiting at the little fish and chip shop a few yards up. The couple had been seen to cross the bridge over the Peak Water. According to the statements, they'd seemed very relaxed, and had stopped, as everyone did, to listen to the water rushing under the parapet as it tumbled from the mouth of Peak Cavern.

But, as Fry had pointed out, that was when the Pearsons were on their way in to Castleton, not out of it. It was merely confirmation that they'd arrived on foot. It gave no indication how they'd left. They had talked about the Limestone Way, and that was the safest route back to their cottage in bad conditions, wasn't it?

Yet it was perfectly possible that the Pearsons had taken the other route. If they'd left Castleton the same way they'd come in, they would have gone over the slopes of Hurd Low and found themselves on the edge of Oxlow Moor. Their route should have connected them to the Limestone Way to the east, and a straight run back to the cottage at Brecks Farm. But what if they'd strayed to the west? With no landmarks or reference points to guide them, it would have been all too easy. Once you'd lost your way in those conditions, you could walk round in circles for hours and be none the wiser.

There was a track to the west, too. He pictured the Pearsons struggling across the snow-covered heather, stumbling over rough ground and finally feeling a path under their feet. They would have followed it, surely. If they were desperate enough by then, they would have grasped at it like a drowning man sighting an oasis.

He shook his head in dismay. But all that did was widen the search area dramatically. His suggestion would not be welcomed.

Yes, the Pearsons would probably have found it easier to follow the track to Hurd Low, but it would have meant leaving the lights of the town behind sooner, as the trail started in Cavedale, deep below the ruined walls of Peveril Castle. If they'd walked over Hurd Low on their way to the George, it would have seemed logical to go back the same way.

Logical, but possibly fatal.

He'd lost sight of Villiers now, so he redialled her number.

'Carol?'

'I'm going through the gate into the dale,' she said.

'Cave Dale?'

'Yes. It's pretty gloomy in here, you know. Lots of dark corners among the rocks. Caves, even.'

'Well, that's why it's called Cave Dale.'

'Right. I was just thinking it would be an ideal location for an ambush.'

'Ambush? Is that your military training coming out again?'

'I suppose so.'

'Who would want to ambush the Pearsons?'

'I have no idea,' admitted Villiers. 'I'm just using my imagination. Isn't that what you do, Ben?'

'I wouldn't always recommend it,' said Cooper.

'The start of the Limestone Way is straight ahead. There's no missing it once you're in the dale.'

'You can come back now, Carol.'

A few minutes later, Villiers opened the door and slipped into the pa.s.senger seat of the Toyota. Cooper showed her the map and told her his theory.

'It's not really a theory,' she said. 'It's speculation.'

'You're right. I know.'

'But I suppose speculation is what we need right now.'

'We don't have anything else.'

They both sat in silence for a moment. Cooper guessed that Villiers was thinking what he was a how disappointing it would be if they went over all the old ground and came up with nothing but the same old facts and the same worn-out theories.

Cooper had never known a case where the events they were investigating were so ambiguous. He could see why the inquiry had eventually run out of steam. There was no firm evidence that the Pearsons had died. Nor was there definite proof that they were still alive and living under new ident.i.ties somewhere.

'The Pearsons both had mobile phones, didn't they?' said Villiers. 'Why didn't they make an emergency call?'

'Yes, that was looked into, of course. David had an iPhone.'

'Oh yes. At the George, they said he was using it constantly to access the internet, to read emails and even to look at maps of the area with its GPS feature. The staff overheard Trisha telling him that he would run the battery down.'

'Well if he was using GPS when they walked across the moor, it would have drained pretty quickly,' said Cooper.

'That would be the phone found buried in the peat.'

'Yes, that was David's. As for Trisha, she had a smartphone too, but she was on a different network. According to the phone company's records, her handset wasn't logged on during the relevant time. It seems likely that she couldn't get a signal. It isn't unusual in that area. Heck, it isn't unusual anywhere in this part of the county.'

'So where is Trisha's phone?' asked Villiers.

'We don't know, do we?'

'No.'

Villiers looked thoughtful. Cooper waited, watching her expression, trusting her to put her finger on some significant point. Or at least hoping that she would.