They walked on. ‘There were over a hundred and fifty thousand Jews in Berlin in the early 1930s, you know. Half of them left the city, and since the war started, they’ve been sending the others away, a thousand at a time, by train – many of them from Anhalter station, near the hotel.’

‘Where are they being sent to?’

‘Keep your voice down, Peter. Here’s the park, let’s go down this path. Where are they being sent to? Who knows? I never ask, I just hear things. There are terrible rumours about them being transported to special camps in the east, where many of them are killed. I don’t know how true it is, but it wouldn’t surprise me; after all, the Nazis have always said they want to annihilate the Jews. When you asked me in Copenhagen why I’m helping the British – well, perhaps that helps answer your question.’

They were inside the park now, and Otto pointed to an isolated bench.

‘Anyone following us will hate this. They’ll have to keep their distance; they’re not going to be able to get near us without looking ridiculous. At least we can now talk properly. The irony of that Nazi telling me the smell was due to the Jews is that the city smells even worse now that they’ve almost all gone!’

‘Perhaps it’s the smell of Nazis?’

‘Exactly, Peter, exactly.’

‘What’s happened to all the trees? So many appear to be missing.’

‘I think some must have been destroyed in the bombing raids, but others would have been chopped down for fuel. That will really hurt the Berliners, having to cut down trees in their beloved Tiergarten. Now, let me tell you about Bruno, my contact here.’ Knudsen removed his hat and placed it on his knee, turning it round to find the right position. ‘I’ll tell you what, why don’t we speak in German? If it’s too difficult to follow, just tell me, but it will be useful for me to have an idea how fluent you are.’

Prince nodded and unbuttoned his raincoat, also removing his hat. Despite the time of year, it wasn’t cold.

‘Feuchtwanger and Wolff was an engineering company founded in the 1890s. They were originally based in Potsdam but moved to Spandau around the turn of the century. Do you know where Spandau is?’

‘I’m afraid not.’