Then the wall just burst apart like a tower built by a toddler. Stones flew everywhere and black liquid poured out in a thick torrent. The headstone nearest the wall – Lucy Pickup’s stone – slipped closer and closer and then fell, cracking in two as it landed not three feet from Tom. Earth poured over the slope where the wall had been and a stench of drains and rotting things almost choked him.

The girl was continuing to back away. Tom took a step forward and something landed heavily beside him, missing him by inches and throwing him off balance. Falling to the ground, he recognized the edge of a coffin, a fraction before the wood collapsed completely and revealed its occupant.

The skull grinned at Tom with tiny white teeth. Pieces of flesh, like old yellow leather, still clung to it. Tom scrambled away from the corpse, feeling the scream build inside his head and knowing that if he let it out he might never be able to stop.

A fresh flood of earth poured down on him, filled with pale-coloured objects that he knew could only be bones. He threw back his head and got ready to let the scream out when a beam of light hit his face and an arm grabbed his shoulder. Tom whirled round. A small figure, wearing a yellow raincoat with its hood pulled up tight and carrying a flashlight, knelt beside him. It was Joe.

Tom pushed himself to his feet. Everything in his head was yelling at him to get back to the house, wake his mum and dad, call the police. As he set off for the back door, Joe pulled him back.

‘No, wait,’ Joe shouted, straining to make himself heard above the wind. ‘We have to find her.’

‘It’s too late,’ Tom yelled back. Up in the churchyard there was no sign of the dark figure. ‘She’s gone. We have to get Mum and Dad.’

Joe shone the flashlight on the ground around their feet. Tom wanted to yell at him to stop. It was all so much worse when you could see it properly. The skull, now broken away from the rest of the corpse, lay a few yards away. Lucy’s tiny statue had fallen along with the rest of her grave. Pieces of coffin were scattered around. He saw what he thought was a human hand, the finger bones clenched in a fist.

Joe seemed to be looking for something. At last, the torch flickered on the black bag which the intruder had tried to escape with. It was half buried beneath a pile of mud and stones. With a cry, Joe ran towards it and started tugging at the handles. Still desperate to get away, Tom had a sense that this might be important. Gingerly, he picked his way over to help.

With a glooping noise, the bag came free and the boys staggered backwards, still clinging to the straps. Joe dropped to his knees and started to tug at the zip. Squeaking with frustration, he finally managed to wrench it back. Then, in the pale light of the torch, Tom could see him grinning. He dropped to his knees beside his brother and peered inside. Millie lay in the bag. As the boys watched, her eyes flickered open. She blinked up at her brothers in astonishment as raindrops began to fall on her face.

SOMETHING WAS THUDDING LOUD INSIDE HARRY’S CHEST. Not his heart, though, his heart never made this sort of racket. Should he say something, tell them he knew the identity of one of the dead children?

It was almost painful, this pounding against his ribs. If it was indeed his heart, he had a serious problem. Hearts weren’t supposed to beat this hard.

He couldn’t say anything now, he’d sound ridiculous, hysterical even. Tomorrow would be soon enough. He glanced down to make sure he would step on matting, and moved away from the cordoned area. The white-clad figures around him got back to work.

The Fletchers’ back garden was a quagmire. Harry followed in Detective Chief Superintendent Rushton’s footsteps, along the loose-weave steel path that had been laid over the mud. Above their heads a makeshift PVC shelter was holding back the worst of the weather. Powerful lights on steel poles had been positioned in the four corners. Now that he was facing the house, Harry could see lights on in the downstairs windows. The blinds and curtains had all been drawn.

‘As crimes scenes go, this is as bad as it gets,’ said Rushton as they walked back towards the house. ‘We’re working in the dark, in shocking weather, the mud’s close to a foot deep in places and it looks like there was quite a lot of contamination of the site before we got here.’

One of the white-clad figures was moving slowly round the outside of the inner cordon, taking photographs. Another figure, which Harry thought might be a woman, was using a measuring tape. She stretched it from the wall to the smallest of the three bodies, then began scribbling, or maybe drawing, on a clipboard hanging around her neck.

‘The forensics people you see have just arrived from Manchester,’ explained Rushton. ‘We don’t have that sort of specialism locally. Luckily, the first officer on site was a bright lad. He sealed off the area until the team could get here. Did the same up in the churchyard.’

Harry looked up. More white figures could be seen on the other side of the stone wall. Up there, too, efforts were being made to control the weather. An awning had been stretched across metal poles. One of the officers was struggling to fasten plastic sheeting around the edges. In this wind it was close to hopeless.

‘What are all these people doing?’ Harry asked.

‘The photographer is recording the scene before the trace-evidence people can get to work,’ said Rushton. ‘He’ll take pictures from every angle, then he’ll climb up into the graveyard and do the same. That girl over there, she’s sketching. She’ll measure how everything is situated in relation to everything else and then it’ll all be fed into a computer. We’ll get a very accurate model that we can use if we ever need to go to court. The main task tonight will be removing the bodies, intact if possible, and getting them to the pathology unit. Along with everything else that might be relevant. The coffin will go, of course, any bits of clothing, hair and so on. We’ll take casts of any footprints. Looks like they’ve started already.’

Rushton was pointing to a spot not far from the house. A man was kneeling on a mat of chequer-plated aluminum, pouring liquid on to the ground in front of him.

‘The other two bodies could have come from graves on either side of Lucy’s,’ suggested Harry. ‘I can’t tell you whose they were, but there’ll be a plan somewhere.’

‘We have it already,’ said Rushton. ‘Family graves on both sides, three people recorded as being in the one, four in the other. All adults. And from what we can see so far, those graves are still intact.’

‘Is it possible they’ve been in the ground a long time?’ asked Harry, knowing it wasn’t. None of the corpses he’d just seen was properly skeletonized. ‘In a much earlier grave that no one knew about? This churchyard is hundreds of years old. There must be ancient graves all over this hill. Headstones got removed, people forgot who was in the ground.’ He stopped. He was gabbling. And clutching at straws.

‘Well, we can’t rule it out for now,’ said Rushton. ‘But frankly, the team think it unlikely. And you have to see their point. Did they look like ancient corpses to you?’

Harry looked back over his shoulder. ‘Do the Fletchers know what’s going on?’ he asked. ‘They’ve been under a lot of pressure lately, it won’t be the best-’

‘Oh aye, they know,’ said Rushton. ‘It was the kids that brought the wall down.’

‘What?’

‘I haven’t had chance to speak to the parents yet, so I’ve only had half a tale,’ said the detective, ‘but it seems the two boys were out in this weather, climbing the wall. They had their younger sister in a hold-all, apparently. Looks like some sort of attempt at running away from home. Job for Social Services, if you ask me. Where are you going?’