‘A lot of digging,’ Howell said.

‘Well, OK, but I wasn’t told about any digging and as of now I haven’t seen any paperwork to that effect.’ He looked from Thorne to Howell and back again. ‘I mean, I’m sure you’ve got the necessary permissions.’

Thorne said, ‘I don’t understand.’ He was trying to sound cheerful, to appear mildly bemused at what was happening, but a heaviness was already starting to gather around his shoulders.

‘Look, I’m sure it won’t be a problem.’ Burnham’s eyes were flicking nervously towards Batchelor and Nicklin, towards their handcuffs. ‘Why don’t we get everyone inside, get some refreshments organised and we can sort everything out.’ He turned and walked back up the track, leaving Thorne and those behind him with little choice but to follow.

‘What the hell’s going on?’ Holland asked.

Thorne shook his head. The heaviness was growing, the irritation becoming something far stronger. The nausea on the boat had quickly put paid to the good mood he’d been in after reading the extracts from Nicklin’s letters, and now there seemed little chance of it coming back.

They walked up the track, then up a short flight of weathered steps to a small stone building. The sign on the door, white letters etched on to black slate, read YSGOL.

‘The school,’ Burnham said.

‘So how many kids are there here?’ Thorne asked.

‘Oh no, it’s not used any more.’ Burnham pushed the heavy wooden door open. ‘Not been a school for sixty-odd years, but we still call it that. You should all be comfortable in here. It’s as good a place as any to use as a base, I would have thought.’

One by one they walked through the outer door, turned sharply right and trooped through another into a damp-smelling hall which, even when the school had been fully functional, could not have seated more than a dozen children. The dark parquet flooring was worn and had come away in several places. There were cupboards lining a whitewashed wall, while the grimy windows in the other allowed no more than the suggestion of light in from the outside. At one end of the room, beneath a small stage area, was a piano covered in a filthy dust sheet, directly opposite a trestle table which had been set up near the door and laid with a shiny plastic tablecloth. A hotplate was connected to a gas bottle. Pump Thermos flasks of tea and coffee sat next to a large bottle of milk and a bag of sugar. There was a tray of sandwiches covered in cling-film.

‘Just help yourselves,’ Burnham said.

Before any of his team could take up the offer, Thorne raised a hand. Said, ‘Can we just get this permission business sorted out first.’

Burnham explained that the island was actually administered by a privately funded trust, dedicated to protecting its wildlife and archaeological heritage. ‘I’m just the manager really,’ he said. ‘But I’ve not been told anything about digging and obviously that’s problematic.’

‘Why?’ Thorne was making less effort to hide his irritation. ‘Why is it problematic?’

‘The island’s an area of Special Scientific Interest. It’s also a place of huge religious significance. There are rules and regulations.’

‘I was told I couldn’t bring cadaver dogs,’ Howell said. She pulled off the cap she had been wearing to reveal ash-blonde hair cut very short. She ran fingers through it.

‘That’s right.’ Burnham blanched a little at the word. ‘There are strictly no dogs allowed on the island.’ He stepped forward and laid a hand on Thorne’s arm. ‘Don’t worry, I’m sure it’s just an administrative snafu of some kind. I’m sure your boss or whoever it is will have completed the necessary paperwork.’

Thorne wasn’t so sure. He had known many investigations hamstrung by the failure to fill in a form and convictions overturned because someone forgot to dot an ‘I’ or cross a ‘T’. It was somewhat hypocritical of him to be so irritated, he knew that, because following procedure of any sort was not exactly his strong point. His strengths lay elsewhere and he left it to others to make up for his… failings in that department. After all, there were plenty paid to be little more than pen pushers, so Thorne believed he was justified in counting on them to push those pens in the right direction.

‘What do you suggest?’ he asked.

‘Well, obviously in the first instance I’ll need to speak to the trust director,’ Burnham said. ‘He’s back on the mainland.’

‘I’ll speak to my boss, too.’

‘Yes, good idea. Belt and braces is always the best approach with this kind of thing and like I said, I’m sure it’s nothing that’s going to hold you up for very long.’ Burnham paused, seeing that Thorne was already frowning at his mobile phone. ‘Ah, yes,’ he said. ‘That’s going to be tricky.’

Thorne looked at him. Waited.

‘If you’re Vodafone, you’re completely out of luck. O2 isn’t a lot better, unless you want to go to the top of the lighthouse.’

‘Seriously?’ Holland said.

‘It’s the mountain,’ Burnham said. He nodded towards the window, even though nothing could be seen through it. ‘Blocks almost everything out. Orange is the best bet, but you’ll still need to head along the track for a few minutes until you’re past the line of the peak, then you might be lucky and pick up a signal.’

‘This is ridiculous,’ Thorne said. His contract was with Orange, but his phone still showed NO SERVICE.

‘What were you expecting?’ Burnham used his stick to push at the powdery edge of a loose parquet tile. ‘We’re almost completely cut off here. There’s no running water or mains power. Compost toilets…’

‘Shitting in a bucket,’ Karim said.

‘Basically.’

Thorne reached into his pocket and took out his Airwave radio. Holland and Karim both had them. ‘What about these?’

Huw Morgan stepped forward and peered over Thorne’s shoulder at the unit in his hand. ‘Yeah, those should be OK,’ he said. ‘Not to make calls, mind, and you won’t be able to reach anybody on the mainland, but should be OK for keeping in touch with each other. Switch to the main maritime frequency, you’ll be all right.’

Thorne turned to look at him. He had forgotten that the boatman was still with them.

‘We’ve got a receiver up at the lighthouse,’ Morgan said. ‘We can listen in on the boats doing illegal fishing. See, it’s only me and my dad supposed to lay the lobster and crab pots round here, but that doesn’t stop plenty of others trying to muscle in —’

Thorne had no wish to get dragged into a dispute about fishing rights. He held up a hand. Said, ‘Let’s get this done then.’

‘I’ve got a satellite phone across at the observatory office,’ Burnham said. He saw Thorne shaking his head. ‘I don’t tend to carry it around with me.’

‘Well, I’d be very grateful if you kept it with you from now on,’ Thorne said. ‘In case anyone needs to get hold of me and I don’t happen to be at the top of the lighthouse.’

‘Yes,’ Burnham said. ‘Absolutely not a problem.’

Thorne walked towards the door, still staring at his phone. Fletcher and Jenks were already making themselves tea and Karim was ripping the cling-film off the sandwiches.

‘Like I said, if you keep walking up towards the abbey… towards the ruins, you should hopefully start to get a signal in a few minutes…’

After being cut off twice and perching precariously on a low drystone wall, Thorne managed to get through to Russell Brigstocke long enough to hear the DCI swearing for almost half a minute without drawing breath, then blaming it all on the detective superintendent.

Thorne wasn’t surprised.

You didn’t get very far up the greasy pole without learning how to pass the buck. He suspected that there was a course you were encouraged to attend as soon as you were promoted beyond inspector. A weekend of seminars in buck-passing, with refresher courses in fence-sitting and advanced arse-licking thrown in for the extra-ambitious. Brigstocke promised he would get everything sorted as soon as he was off the line.