‘We haven’t had any raids recently, but if there is one, I urge you to take it seriously.’ The concierge dropped his voice and moved closer to them, as if he was imparting something confidential. ‘Last September they destroyed Potsdamer station, just across the road from here. Most of our windows were blown out. Of course,’ he smiled, exposing a mouthful of yellow teeth, all at different angles, ‘we are defeating the enemy, but in the unlikely event of a raid while you are our guests, there are three bomb shelters in the hotel. Please allow me to show you where they are.’

‘Just keep walking, Peter. We’ll have a proper chat once we’re in the park. In the meantime, it’s not a particularly good idea to stare for too long at the bombed buildings, and don’t take too much notice of soldiers either – especially if they’re wearing black uniforms like those over there: they’re the SS. Remember, we’re most probably being followed, so this needs to look like two colleagues out for a stroll.’

After leaving the hotel, they’d headed up Saarland Strasse to Leipziger Platz and then north along Hermann Göring Strasse. Apart from the pale yellow trams, almost all the traffic was military, lorries moving noisily through their gears, armoured cars acting as if the road belonged to them, and the occasional long black Daimler or Horch with curtained rear windows and a motorbike outrider. Ahead of them loomed the Reichstag, its grim blackened exterior setting the mood for the surrounding area.

No one made eye contact and everyone seemed to be in a hurry: it was as if every pedestrian had been permitted an unreasonably short period of time in which to reach their destination. Prince couldn’t quite place it, but there was an unfamiliar smell to the city.

‘What’s the smell – it seems unusual?’

‘I’m not sure. I always notice it too: it’s got worse as the war’s gone on. I think it must be a combination of the air raids, the cheap coal they use and the lack of hygiene – it can be quite overpowering at times. You know…’ Otto paused while two women walked briskly past them, as if trying to keep in step with each other, ‘I was here just before the war started in 1939, and even then there was an odour about the city. I was told it was because the place was built on a swamp. I asked one of the Nazis who’d been made a manager at the factory about it and he told me it was the smell of Jews.’