Frau Moser was in a terrible state after that, convinced she’d be arrested, and then worrying about who’d do the farm work. For a few weeks she clearly regretted letting the gentleman from Berlin into her life, spending much of the day sobbing and exhausted from all the extra work she had to do.

It turned out she had no close neighbours or friends and no family other than a sister near Munich who she’d not seen for years. They agreed that if anyone asked, she’d say her husband had returned unexpectedly from the war but had become a recluse and refused to see people.

The Americans arrived in the middle of May. The man who came to collect the milk each day had told Frau Moser they were in Eggenfelden and would soon be visiting all the farms. They turned up a few days later, four men in a jeep who checked the place out and then looked at their papers. They seemed satisfied, and registered them and issued new documents.

After that, matters began to get easier. Wolfgang persuaded Frau Moser to employ someone to work on the farm for a few hours each day, during which time he’d stay in the house. She was less exhausted and slightly calmer.

He spent his days in the cellar, logging the rolls of undeveloped film and reading through the notebooks. The more he thought about his plan and the more he refined it, the more confident he was about it.

By the time they got to July, life seemed easier. No one ever bothered them and Wolfgang found the physical work had a positive effect on his mood. He felt fitter – mentally and physically – than he’d done for years.

Of course he still worried. Someone might discover he wasn’t Andreas Moser after all. And then there was his plan: as good as it was, it could still go wrong. His biggest worry, though, was his son. He had little idea what he was up to and whether he was doing as he’d been told.

The farm did have a telephone – he’d gone to some trouble to have it installed – and his only link with the outside world was Ulrich, a comrade in Frankfurt with an impeccable network of contacts himself, whom Wolfgang trusted implicitly to keep an eye on Friedrich. Once a week he’d telephone him to check whether there was any news.

Is Mother well? When do you think it would be a good time to visit the cousins?

And Ulrich’s replies would be the same.

Mother is well, you’re not to worry. No, now is not the right time for you to visit the cousins.

But in late July, his response was far from reassuring.

Mother is not good, actually: her old condition is playing up.

Wolfgang felt the air turn cold around him.

She was taken ill in Munich. I’m not sure what to do. One of the cousins appears to have found out about her.