He was surprised when the car suddenly came to a stop again. He hadn’t been paying attention to anything other than the man in front of him. Now, he glanced over Radecki’s shoulder through the window. They were in a more remote part of the marina, a much smaller dock with room for only half a dozen vessels. There wasn’t another person in sight. The Mercedes had stopped alongside a steel barge painted battleship grey. ‘Give me a minute, boss,’ Krasic said, climbing out of the car. The boot lid rose, and Krasic disappeared behind it. He re-emerged, tucking a crowbar inside his jacket.

Tony watched with mounting anxiety as Krasic looked around him, then ran nimbly up the gangplank to the barge. He climbed on to the hatch cover and swiftly popped the hasp of the padlock holding it shut. He slid it open and peered inside. Then he hurried back to the car, giving Tadeusz the thumbs-up signal.

‘We’re going to get out of the car and we’re going to board this barge. If you try to run, I will shoot you in the legs. I am a very good shot, Dr Hill,’ Tadeusz said calmly. ‘There’s no point in shouting either. This place is deserted.’

Krasic opened the door and Tadeusz backed out, never taking his eyes off Tony, who slid across the seat and out of the car. Krasic grabbed him by the shoulder and swung him around. The gun was in his back again. He stumbled forward, almost tripping over the edge of the gangplank.

Once on board, he was marched up to the open hatch. Krasic clambered on to the ladder with surprising ease for so bulky a man. He descended into the gloom below. There was the hollow sound of footsteps on metal in an empty space, then a dim glow appeared in the hold.

‘Get down there,’ Tadeusz ordered him.

Gingerly, Tony turned to face him and negotiated his way on to the ladder. He was a couple of rungs down when he felt an excruciating pain in his hand, so sudden and severe he had to let go. His feet went from under him, scrabbling in mid-air for purchase, and for a terrifying moment he swung by one hand. He looked up in panic, seeing Tadeusz’s hand swinging the gun butt towards his clenched fingers. Sweating with fear, he threw his injured arm round the ladder and managed to get one foot on a rung, pulling his undamaged hand out of the way at the last instant. He would never know how he managed it, but somehow he swarmed down the ladder fast enough to avoid any further attrition from above.