‘My instructions are to get into Peenemünde, provide a detailed diagram of the site and remain there to await further instructions. They want me to assume the identity of a French labourer. I have no idea how…’

‘You speak French?’

‘A little: my accent is passable enough, but I’m not sure many people will believe I’m French.’

‘Don’t worry. I’ve been thinking about this, and I have a plan. I have to work tomorrow at the orphanage but I’m free on Wednesday. In the meantime, you need to get as much rest as possible while you can.’

‘What do you think? I know it’s a ridiculously big car, but the important thing is the size of its boot. We could fit two of you in there quite easily.’

Richard Prince climbed out of the boot of the Mercedes-Benz 770, which Sophia had reversed with some difficulty into the garage alongside the villa. There was no question he would fit into the space under the boot with room to spare. She had even placed a rug and some blankets in there to make it more comfortable.

‘It’s around twenty-five miles to the island. I could do it in an hour, but the roads aren’t too good and the checkpoint at Wolgast to get onto Usedom island can take another hour to get through. This will be the fourth time I’ve crossed over, so hopefully they know me by now.’

‘But surely they’ll search the car?’

‘Of course, but they won’t think of looking in that space, and remember, I’ll have various odds and ends on top of it. Before I forget, you’d better give me your identity cards – the Danish and German ones. It will blow your cover if you’re caught with them. I’ll keep them safe for you, don’t worry.’

They left at ten o’clock on the Wednesday morning, having spent twenty minutes ensuring Prince was safely stowed in the space under the lining of the boot. It was more comfortable than he’d expected, though still claustrophobic: he knew he’d be in there for at least two hours, and possibly considerably longer.

An hour after leaving Greifswald, the car stopped. For the first time he could make out sounds around him other than that of the car’s considerable eight-litre engine.

‘Heil Hitler! Good afternoon, my lady: my very warm greetings to you. I didn’t expect to see you again so soon.’

‘Heil Hitler! I had today off, Oberleutnant, and I found my visit to the island on Sunday so peaceful that I felt pulled towards it once again.’

‘And do you have papers, my lady?’