‘Nope. Light blue, seen under the streetlight near the phone box. No reg, but it probably started with an X, so it wasn’t a new model.’

‘You know, we need the media to come on board early in this one, Paul. There are no obvious leads from the house. We’ve got to get appeals out to locate the driver of that Astra, and anyone who had contact with Rose Shepherd in the last forty-eight hours. No – the last two weeks. God, I don’t know – any contact with her, full stop.’

Cooper looked up, surprised to hear the DCI getting even a little bit rattled in public.

But he could see what was bothering Kessen. The first twenty-four hours were the vital period after any murder. If you didn’t have a strong lead within that time, you were destined for a long drawn-out enquiry – and the odds were against bringing the case to a successful conclusion. This murder might be forty hours old already, according to the ME, and there wasn’t a single lead in sight.

But why didn’t someone miss Rose Shepherd? That was the question the DCI had asked earlier. And it was a good question.

‘You know, there’s absolutely no sign of an intruder being in the house,’ said Kessen. ‘Apart from this open window, which shows no traces of having been forced. No tool marks, no damage. Right, Wayne?’

Abbott had his phone to his ear. ‘And no fingerprints either,’ he said. ‘I just got an update. The only prints we found on the window are a match for the victim’s – and they were on the inside.’

‘And every other window in the house is locked down tight. Why wouldn’t this one be locked, too? Can anyone suggest an answer to that?’

‘Yes,’ said Hitchens, looking anxious. ‘Because someone used this window to get out of the house. I don’t know how he got in – I can only guess the victim let him in through the front door. But he must have gone out this way.’

‘We’re on the first floor. Did he clamber down the drainpipe?’

‘Probably.’ Hitchens looked out of the window. ‘Actually, there isn’t a drainpipe. Not within reach.’

‘A nice dense ivy, then? Russian vine?’

‘Nothing. It’s a blank wall …’ Hitchens hesitated. ‘He must have jumped.’

‘From this height?’

‘Er, yeah.’

‘In that case, Paul, I expect you’ll find the intruder’s prints on the window frame, perhaps some fibres from his clothes on the stone ledge. There’ll be some pretty deep footwear impressions in the ground down below, where he landed. Oh, and you’ll be looking for a suspect who ran away with two broken legs and a cracked spine.’

Hitchens sighed. ‘So what’s the alternative?’

Kessen joined him at the window. ‘There’s only one other possibility. That there never was an intruder in this house. The victim was shot from outside.’

Hitchens stared. ‘From the garden?’

‘No, look – the angle is completely wrong. The shots must have come from the field.’

‘But the window – why was it open?’

‘Wayne said there were no prints on the outside. What about the inside?’

‘Just the victim’s.’

‘So that’s pretty clear, isn’t it?’ said Kessen. ‘The victim opened the bedroom window herself. And someone waiting in the field shot her.’

‘Jesus,’ said Hitchens.

Kessen turned back and addressed the room in general. ‘Close off that road up there, seal the gateway, and get the SOCOs and the search teams into the field. That’s where our gunman was.’

Before the action moved outside, Cooper took a chance to study the interior of the house. One of the first things that had struck him was the amount of dust. Of course, there had been no cleaner. And Miss Shepherd had only done the minimum amount of housework herself, by the looks of it. A bit of attention to the sitting room, the kitchen, the bathroom, and her bedroom.

But there were other rooms that seemed to have lain untouched. Opening the door into a guest bedroom set balls of dust rolling across the carpet, spiders scurrying away from the movement. The curtains were closed in here, so Cooper switched on the light. Fine particles of dust hung in the air, swirling in the draught from the landing.

Most people had no idea where the dust in their homes came from. As far as the average householder was concerned, it might as well come from the Moon, floating down from the sky every night and settling on available surfaces like drifting snow. An inconvenience, perhaps, but something natural and inert that was just part of the atmosphere, like oxygen.

But Cooper knew different. It was one of those facts that he’d learned as a teenager and never forgot. He knew that all human beings in the world shed thousands of dead skin cells every hour, an entire layer of skin over three days. That was what hung in the air and danced in a shaft of sunlight from the window. That was what lay on the shelves and gathered in restless clumps under the bed, or shrouded the junk in the attic. Ninety per cent of the dust in any house consisted of dead human skin.

Also, the décor in the sitting room struck him as odd. Off-white and charcoal grey, almost no colour. It seemed a bit modern for a house of this age, let alone for the sort of woman that Rose Shepherd seemed to have been. As far as anyone could tell, anyway.

Hitchens stuck his head round the door. ‘Ben, we’ve brought the postman back to the scene. Go and get a statement from him, will you? He’s fretting about getting back on his rounds.’

‘Right, sir.’

Cooper took a last look at the charcoal grey wallpaper around the fireplace. It showed up the dust badly, and it was undisturbed by finger marks. And then he remembered another fact he’d learned about house dust. Each speck of it carried tens of thousands of dust mites. Right at this moment, they were busy feeding on those dead skin cells.

6

‘Years ago, I used to work on a delivery round out Leek way,’ said Bernie Wilding when Cooper found him sitting in his red mail van. ‘I saw those wallabies out there about as often as I saw Miss Shepherd in Foxlow.’

‘The wallabies?’

Cooper laughed. Most rumours of exotic animals surviving in unlikely parts of the country were rubbish. But sometimes the creatures turned out to be real, like the scorpions on the London Underground – or the wallabies of the Roaches.

‘Did you really see the wallabies?’ he asked.

‘Only as an odd shape in the distance once or twice. I was never quite sure whether I was looking at a wallaby or a hare, really. But I always told everybody I’d seen the wallabies. Well, you do, don’t you?’

‘Yes, I would too.’

It was one of Cooper’s genuine regrets that he’d never seen a wallaby, despite his thirty years in the Peak District. No one who lived or worked on the western fringes of the national park doubted they existed. Plenty of drivers had seen them, and a few had run one over at night on some remote road. The original animals had escaped from a private zoo during the Second World War, and bred on the moors. According to the stories, a yak escaped at the same time. But the last yak sighting was back in the fifties. Pity, really.

‘Too late now, I reckon,’ said Wilding.

‘So they say. Too many people and dogs invading their habitat.’

‘Oh, aye. And too much traffic. People have killed them off, when the bad winters couldn’t.’

Cooper thought he’d probably passed the test. Some of his colleagues would have had no idea what Bernie was talking about. But he’d proved his credentials as a local.

‘What about Miss Shepherd? You saw her often enough and at close enough range to recognize her, didn’t you?’

Wilding screwed his face up thoughtfully. ‘You know, the few times I did catch a glimpse of her, she always seemed to be wearing a headscarf, or something that hid her face. I could never be entirely sure it was her. Not so that I could absolutely swear to it, you understand?’