‘It won’t get to London before late Monday at the earliest, more likely Tuesday or Wednesday,’ Hanne told him. ‘By the time they get back to us, it could be another week. You’ll just have to stay here. I’m sure I can find plenty of ways to amuse you!’

The response from London took longer than expected, and it was the weekend before Christmas before they finally heard back.

London very much appreciates Agent Laertes’ report.

Agent Laertes will understand that a number of issues remain unresolved: there are still questions to be answered.

Therefore, he is to travel covertly to Germany and gain entry to the Peenemünde site.

Because of the uncertainty of travel over Christmas and the New Year, he is to leave Copenhagen on 4 January.

He is to assume the identity of a French slave labourer.

He is to supply detailed information on what is going on at Peenemünde and provide a detailed diagram of the site.

He is to remain at Peenemünde until otherwise instructed.

En route to Peenemünde he is to meet an agent in Greifswald: this agent will facilitate his entry to the camp and receive his communications when he is there. Further instructions to follow.

On his return to Copenhagen, London will be very happy to arrange his return to England.

It took Prince a few days to get over the shock of this message: instead of spending Christmas with his son, he would be remaining in Copenhagen. That was bad enough, but the prospect of travelling back into Germany – a journey London had helpfully described as covert – was hard to contemplate. And as for gaining access to Peenemünde… just the thought of it terrified him. Even if he got in, he doubted he’d ever get out. He felt none of the excitement he’d experienced in anticipation of the Berlin trip.

Hanne was adamant he should remain in the apartment until he started his journey. They could never be certain that his Peter Rasmussen identity hadn’t been compromised. No one knew where he was staying: Otto Knudsen was unaware of it, and the address on his legitimationskort was that of an apartment that didn’t exist in a large and mostly deserted complex on the other side of Vesterbro.

Hanne spent much of the Christmas period at work, covering for colleagues who wanted to celebrate with their families. On Christmas Day, she visited her father. As much as she wanted to be with Prince, they both realised that if she spent too long in his apartment rather than her own, it could arouse suspicion.

Nonetheless they did have a good deal of time together, the physical passion unabated and bringing with it a genuine love, one they clearly shared.