They were woken at six the next morning and marched out of the building before being split into four groups. Prince’s group walked for a mile into the town centre and stopped in front of the shell of what looked like an office block. They were ordered to take a shovel each and start clearing the rubble.

For the next two weeks, that was life in Lübeck: clearing rubble for ten or eleven hours at a time, the back-breaking work and sheer tedium occasionally broken by being sent on a detail to sort bricks and select ones that were considered to be more or less intact. All the time they had to watch out for the guards, an embittered bunch of thugs and sadists who’d look for any opportunity to abuse the prisoners.

One afternoon, Prince was part of a group sorting out a pile of bricks in a vast arched doorway, all that remained of a church. He was standing next to Henk, the Dutchman who’d been in his hut in Neuengamme and who’d survived because of his love for his wife. Henk had found an old rag, which he’d fashioned into a glove to protect his hand as he picked up the rough bricks. One of the guards swaggered over, a short man in his fifties with a red face.

‘What the fuck are you doing?’

‘Sorting bricks… sir.’

‘I meant, what’s that on your hand?’

‘It’s to protect it: it means I can work faster.’

‘Take it off.’

‘Why, so I work slower?’ Henk smiled gently at the German, assuming he’d be grateful for the explanation.

‘You think you’re clever, eh? You insolent bastard…’ The guard grabbed the brick from Henk’s hand and smashed it into the Dutchman’s temple. Henk staggered back, and Prince moved to support him, but the guard had pulled his pistol out.

‘You, step back, leave him.’ Henk was slumped on the ground now, blood pouring from his head, his eyes barely open. ‘Get up!’

For a brief moment, Henk tried to rise, but the effort was too much and he collapsed to the ground again. The guard walked over, held the pistol close to his head and shot him. Then he turned and pointed his gun at the others. ‘Who’s next?’ No one said a word.

At that moment, an SS officer walked over. He told them to carry on with their work, and Prince could hear him reminding the guard that they needed as many prisoners as possible.