‘Well, I wouldn’t know. He wasn’t a Nazi Party member in 1936, otherwise they wouldn’t have sacked him, but you’ll understand that I’ve never discussed politics with him. You simply don’t do that here. However, I always got the impression – and it’s only an impression, Peter – that he’s not a Nazi. The phrase he constantly uses is “I’m only an engineer”, but over the past couple of years there has been the odd remark. He may refer to food shortages, or a neighbour’s son missing in the east, or having to be careful when he speaks in front of the children. But you must realise, I do nothing to embarrass him: I don’t ask questions or discuss the war. It’s a cordial relationship certainly, but a guarded one, and more than anything else, it’s business.’

‘So how did the meeting with the Luftwaffe officer come about?’

Otto frowned, thinking about his answer. He waited while a woman walked past with her dog, the first person to have been near them in a while.

‘I’ve no idea, and to be honest, I still don’t know quite what the meeting was about. I don’t usually socialise with Bruno outside of work: they’re long days and he wants to get back to his family. I’m usually tired and I prefer to stay around the hotel, eating there. I have been to dinner with him once or twice, though, so it was not so unusual when… hang on, Peter…’

A shabbily dressed man shuffled past them, doffing his hat as he did so. His stained raincoat was tied up with a length of rope and his shoes were filthy.

‘Guten Nachmittag.’

They wished him a good afternoon in return, but he’d paused – more or less stopped, in fact – when he’d greeted them and looked as if he wanted to linger. When he eventually walked on, he turned round a couple of times, checking they were still there.

‘Gestapo?’

‘I’m not sure, Peter. How old would you say he was… mid-thirties? Quite young not to be in uniform. Where was I? Ah yes, so on the trip in August, Bruno suggested we go out to a restaurant one night for dinner. Outside of the hotels, it’s hard to get a good meal in Berlin, and it’s always complicated by the fact that you need food stamps too. Those restaurants that are decent and have a good supply of food are very hard to get into. But Bruno said he had a special voucher for a place on Donhoff Strasse and suggested we went there. It was a Bavarian restaurant, I don’t remember the name, and the voucher meant we didn’t need to present food stamps.’

‘Is the restaurant near the factory?’