As he inched his way to the road and turned towards a hamlet called Glutton, Irvine shook his head in frustration. It seemed so difficult these days to know what was the right thing to do or say. Perhaps it was working so closely with Becky Hurst that had done this to him. She’d made him paranoid about blurting out something that might upset or offend anyone listening.

But Becky was right a lot of the time, of course. You had to be careful; what you said, especially when you were a police officer. It didn’t really matter what your personal opinions were, as long as you didn’t act on them or express them out loud. Not even in an email or a tweet. Someone was bound to report you for inappropriate behaviour. It was almost the worst offence you could commit now. No one allowed police officers to be human, not in the way they once had. No office banter or canteen culture pranks, none of that black humour or contempt for criminals the old school coppers had expressed on a daily basis.

You’d think it was unhealthy to keep all this stuff bottled up, though. All those old guys around the station always seemed so much more relaxed. Take Gavin Murfin. He was so laid back he was practically lying dead on the floor. He said what he thought and didn’t care about the consequences. He’d already put in his thirty years’ service and could pack his belongings at any moment with the certainty of collecting his full pension.

Irvine couldn’t imagine ending up like that. The job was so different now. You had to keep your lip buttoned if you wanted to survive long enough to call it a career. If he managed to make it to his thirty, Irvine suspected he’d be a screwed-up, paranoid mess. Probably a chief superintendent, in fact.

He drove the Vauxhall up out of the valley and through some of those curiously shaped hills that characterised this side of the county. Earl Sterndale was only a little way ahead. He was glad of the satnav’s instructions when it came time to make the turn. The crossroads were almost anonymous and unrecognisable.

The Beresfords’ house was a stone-built semi near the village church. He was able to park directly in front. But he waited for a few minutes, watching children leaving their homes and walking down to the bus stop to wait for the school bus. It made him feel like a lurking paedophile and he began to worry that a suspicious parent might take his registration number and report him.

Finally, he couldn’t waste any more time. He climbed out of the car and checked his pockets to make sure he had his notebook, his warrant card and his phone. It was as he was looking down that he noticed his shoes were caked in mud. So were the bottoms of his trousers. There must be mud on the carpet in his car too, damn it. Just as bad was the fact that he now had to present himself at someone’s front door in this state and expect to be taken seriously. There was no point in trying to brush the mud off until it dried. Anything he did now would only make it worse.

Irvine cursed under his breath. He heard laughter and turned to see a couple of girls about thirteen years old walking past. They were giggling and nudging each other like idiots. He felt himself beginning to flush. He was glad his DS couldn’t see him now.

He knew Ben Cooper had wanted children. Wanted them badly, in fact. Irvine had once run into Cooper on the street in town, when they were both off duty. It had been in Clappergate, near the entrance to the shopping precinct. He remembered the encounter well, because it had been one of the moments when details impressed themselves on his mind.

Cooper had been accompanied by his two nieces, the younger one holding his hand, the other a bit too old to do the same without embarrassment, but sticking close by his side. Irvine had tried to make polite small talk, the way you were supposed to. But he’d felt very awkward, and even a bit shocked, at this terribly domestic picture of his detective sergeant standing in the street like a proud dad.

Maybe it wouldn’t happen for Cooper now. He might never have his own children to take shopping. Irvine was sure it must be what Cooper was thinking.

Irvine didn’t like children much himself. He didn’t possess that urge to be a parent. He couldn’t help a horrified reaction to mothers sometimes. It was the way they seemed to regard motherhood as giving them not only special privileges, but some kind of superpower. Their sense of entitlement could be staggering and they instilled it in their children too. He’d never been brought up like that. Back home in Yorkshire he’d been taught a bit of humility and consideration for other people. It made him feel like some old fogey to be looking at these arrogant young kids and dreading what sort of society they’d create when they grew up.

At least he couldn’t picture Becky Hurst as a mother. It would be far too disruptive to her future plans.

He turned his back on the girls, surreptitiously wiped his shoes on a patch of grass and went to knock on the Beresfords’ door.

Once the search area was extended, it didn’t take long for the search teams to turn up their first find. When the shout went up from somewhere deep among the trees, Cooper felt all his senses prickle with anticipation. It was as if a shot of adrenalin had just gone through his veins. All the tiredness fell away like dead skin. There was an edge to the tone of the voices he could hear from the woods. It told him what he’d been waiting for. This was going to be something that would change the whole picture.

‘What have you found?’ he asked when he’d run up the slope to the point where the shout had come from.

‘Look for yourself, Sergeant.’

Cooper pushed through members of the search team and looked. There was another trackway here, descending the hill diagonally from the north-east. There was very little trace of the stone setts, if there had ever been any. But the track was marked by a low wall on the side where it overlooked the valley.

Just at the point where this route dipped to approach the Corpse Bridge, a large slab of stone was embedded in the ground. Its top was flat and smooth, and it must have been almost six feet in length. On its own it looked anomalous. It was obvious that it had been sited here deliberately, but a long time ago. Over the centuries it had weathered and become scarred and worn by use. Its mossy sides blended in with its surroundings, but it had clearly been important. It was functional, not decorative. And Cooper knew what it was.

‘A coffin stone,’ he said. ‘They would rest the coffin here before they crossed the bridge.’

The officers in the search team were looking at him expectantly now. That was the trouble with sounding as though you knew what you were talking about. Sometimes you didn’t. Sometimes you were as baffled as everyone else.

‘But as for that,’ said Cooper. ‘I have no idea.’

Lying on the coffin stone was a makeshift dummy. It was an effigy stuffed with straw or cotton wool, stitched into an outfit of clothes that looked to have been made for it specially – brown corduroy trousers, a tweed jacket, a floppy hat.

‘It’s a guy,’ said someone. ‘That’s what it is.’

Cooper nodded. Yes, in some ways, it was a traditional Bonfire Night guy, the sort of thing that would be on bonfires all over the country in a few days’ time. But most of them would be much less carefully crafted than this one. There was something chilling about the amount of effort that had gone into creating the features of the face. He felt sure it was intended to resemble some real person, though it was no one he recognised. What message was it intended to convey?

The effigy lay sprawled on its back on the coffin stone, its limbs bent into unnatural shapes, its torso wet and beginning to cover over in dead leaves. The unnerving face was grinning up at him from amid the first stages of decomposition.