And while he could have conceivably said no at that point, he knew he’d have regretted doing so. Every time he saw a soldier or an airman, he felt a pang of conscience, a sense that he wasn’t playing his part in the war. He knew that but for Henry he’d have joined up long ago.

‘Two months you say, sir?’

‘More or less, yes. I mean, clearly we won’t be counting days as such, but…’

The Chief Constable made a snorting sound.

Prince took a deep breath. ‘Well, I suppose so, yes…’

Hendrie had stood up rather too fast and walked over to him and clasped his hand with both of his own. ‘Welcome on board, Prince. Perhaps you and I can find somewhere to have a chat?’

In other circumstances Richard Prince would have described the three weeks near Matlock as being rather pleasant. The house was very comfortable, a couple employed by the Service were there to look after the place and cook the meals and the countryside was stunning. A man called Martin gave him firearms and self-defence training along with sessions on communications. Hendrie’s job, apart from fussing around and worrying about security, was to brief him on the mission and initiate him – as he put it – in the ways of an agent on a clandestine operation. A Danish woman called Greta was there from time to time too: her job was to help construct his new identity and ensure he was familiar with all things Danish.

Prince and Greta Poulsen became close during her visits to Derbyshire. He wasn’t able to tell her anything about himself and she only knew him as Thomas – Hendrie was the only person there aware of his true identity. But she was friendly, in contrast to Martin’s businesslike approach and Hendrie’s fussing around. They went for long walks in the countryside and after a couple of days she would link her arm through his. Soon after that, she took to kissing him on the cheek when they met and when they parted.

Prince hadn’t anticipated how much this friendship would mean to him, and he even came close to telling her about his circumstances. He thought about it as they walked down the lanes and across the fields: of course he wouldn’t give his name or any other details, but he could hint at a recent tragedy involving his wife, and maybe even refer to a child – he’d avoid saying it was a son. It might help explain a certain reticence she’d have been bound to have spotted in him. He didn’t want her to think of him as being rude.