After a long few minutes, the track began to get wider and flatter and the sea appeared in front of them suddenly as they rounded a sharp corner; brown between grey outcrops of rock. Several vehicles were parked in a line along one side of the track, while directly ahead at the edge of a concrete slipway, their transportation was being prepared for departure. Thorne parked up carefully, sat there for a moment or two and studied it. He had been expecting something that conformed to his idea of what a ferry was, but the only vessel he could see looked a lot more like a bog-standard fishing boat. Thirty or forty feet long at a push, bright yellow where it wasn’t dirty or rusting, and sitting on a trailer.

‘Is that it?’ Jenks asked. ‘Bloody hell…’

Thorne watched a man climb down from the boat and trudge through the mud to a stockpile of large plastic canisters. He picked one up, carried it back to the boat and heaved it part way up the ladder from where it was collected by a second man waiting on the deck. Thorne guessed that the liquid slopping about inside was oil.

‘Don’t be disappointed if there isn’t a cocktail lounge,’ Thorne said.

As he climbed out of the Galaxy, Thorne saw two people emerge from a mud-spattered Land Rover that had probably been white to begin with. He nodded across, guessing who they were. They came over and the woman who had led the way introduced herself.

Professor Bethan Howell was a forensic archaeologist based at Bangor University, who had been assigned to the team by North Wales police. She was a little below average height and perhaps a few pounds above the average weight for it. She wore wire-rimmed glasses and a baggy, black cap and, in an accent rather more mellifluous than some he had heard the night before, she told Thorne that the job sounded interesting, that she was keen to get to work. She introduced the crime scene investigator she had brought with her, a pasty-faced individual named Andrew Barber. He shook Thorne’s hand and stared out at the water. His expression suggested he had been offered the choice between this job or washing a corpse and now believed that he’d made the wrong decision. Knowing that Howell and Barber ought to get acquainted with the CSM and the exhibits officer, Thorne waved Markham and Karim across from the second Galaxy, then went to make himself known to the boatman.

He shouted up to the man on the deck, who in turn pointed to the man who was still busy ferrying the plastic containers across the sludge.

Thorne walked over and introduced himself.

Huw Morgan was somewhere in his mid-to-late thirties; moon-faced and unshaven, with close-cropped dark hair. He wore dirty grey overalls and heavy work boots and, once he’d shaken Thorne’s hand, he pointed with a thick, grubby finger to the man on the deck of the boat. ‘That’s my father, Bernard,’ he said. ‘He’s the crew.’ When he saw that Thorne was looking at a third man, who was hauling himself up into the seat of a small tractor, he said, ‘That’s Owen,’ as if no further explanation were necessary.

‘Right,’ Thorne said.

Morgan continued loading the containers, while the tractor was driven across and positioned at the front of the trailer and Howell and the others unloaded their equipment from the back of the Land Rover: a small diesel-powered generator on wheels, several large canvas bags, two metal boxes the size of large suitcases and a pair of common-or-garden spades. Helping Howell carry one of the boxes across to the boat, Thorne expressed surprise that she hadn’t brought rather more equipment. He’d certainly been on more straightforward jobs than this one where twice or three times as much gear had needed humping around.

‘No point,’ she said. ‘I’ve made doubly sure there’s everything we’re likely to need. There is a larger boat, apparently… the one they use to take livestock or heavy machinery backwards and forwards, but there’s no vehicles once we get over there, just the odd tractor or whatever. There’s no roads, as such.’ Grunting with the effort, she pushed the box up the metal ladder and Morgan Senior dragged it on to the deck. ‘So, we don’t really want to be taking anything we can’t move around easily.’

‘I had a very short conversation about using a helicopter,’ Thorne said.

‘Nobody willing to splash out?’

‘No chance. Anyway, there’s far too many of us.’

Overhearing them, Morgan shouted from the cabin. ‘Going to be a bit of a squeeze as it is,’ he said. ‘I’m only supposed to carry twelve, tops, and I’ve got all you lot plus all that equipment.’ He glanced down towards the cars; the Galaxy in which Jenks and Fletcher were still sitting with the prisoners. ‘Plus whoever you’ve got in there.’ He saw a worried look pass between Howell and Barber. ‘Don’t worry, we’ll be fine,’ he said. ‘Just won’t be very comfortable, that’s all. It’s a working boat, this.’ He pulled on a grubby-looking green hat. ‘She’s not built for pleasure…’

Once everything had been loaded and as soon as everyone had changed into waterproofs and suitable footwear, Nicklin and Batchelor were brought out of the car. They remained cuffed as they were helped up the ladder. If Morgan was remotely interested in who was being brought aboard his boat, he made a great job of hiding it.

Like he had said, it was a squeeze. The prisoners and prison officers took seats on the narrow metal bench that ran along the edge of the deck, the handcuffs making it dangerous for Nicklin or Batchelor to remain standing. Howell and Barber sat on top of their equipment in the centre of the deck while everyone else found room where they could, grabbing hold of a rope or pole as soon as Morgan told them they needed to.

On Morgan’s signal, the tractor pushed boat and trailer slowly down into the water. Once the boat was safely afloat, the engines grumbled into life and the tractor reversed back up the slipway, taking the trailer with it. Morgan gave the driver a wave, turned the boat around and said, ‘Right then.’

For ten minutes or so, the Benlli III motored steadily out to sea, moving parallel with the Lleyn peninsula. The rain had thankfully stopped, but it still felt bumpy enough to Thorne. He was careful to watch his footing on the slippery deck as he moved forward to the edge of the cabin from which Morgan was steering the boat. He had to raise his voice above the rhythmic grind and thrum of the engines.

‘Lucky with the weather,’ he said. ‘It was pissing down an hour ago.’

‘You’ve got no idea.’ Morgan spoke without turning around. ‘We’ve not been able to run regular trips for months now. In the summer we’ll sometimes do three full trips a day, showing tourists the wildlife, the old smuggling routes, what have you. This time of year, though, it’s a dead loss. It was clear for a couple of days last week, managed to take a birdwatcher across, but otherwise it’s been really bad.’ Now he turned, nodded at Thorne. ‘So yeah, bloody lucky.’

‘Changes fast, does it?’

‘You’ve got to keep an eye on it, put it that way. Like, I knew eventually it was going to clear up this morning, even if it didn’t look that way first thing. That’s most of the job, if I’m honest. No point taking a group across unless I know I can get them back again, is there? I mean, don’t get me wrong, sometimes there’s sod all I can do about it. We had one lot stuck out there for three weeks earlier in the year, but we try not to let that happen too often.’

Thorne said, ‘Pleased to hear it.’ His hands were freezing where he was holding tight to the edge of the cabin door. He dug into his jacket pocket for gloves.

‘A good boatman won’t just know what the weather’s going to be like in twelve hours. He needs to know what’s going to be happening in twenty four hours or thirty-six.’ He nodded out across the waves. ‘Especially with this stretch of water. This can be a pig…’