Only a few metres from the front door to my building were a couple of dress shops where I saw a snail’s long, silvery trail rising high above a tailor’s dummy, while a giant spider’s web threatened to envelope another in razor-sharp gossamer.

Further on, at the corner of Kurfurstendamm, I came across an enormous mirror that lay in a hundred pieces, presenting shattered images of myself that ground and cracked underfoot as I picked my way along the street.

For those like Weisthor and Rahn, who believed in some symbolic connection between crystal and some ancient Germanic Christ from which it derived its name, this sight must have seemed exciting enough. But for a glazier it must have looked like a licence to print money, and there were lots of people out sightseeing who said as much.

At the northern end of Fasanenstrasse the synagogue close to the S-Bahn railway was still smouldering, a gutted, blackened ruin of charred beams and burned-out walls. I’m no clairvoyant but I can say that every honest man who saw it was thinking the same thing I was. How many more buildings would end up the same way before Hitler was finished with us?

There were storm-troopers – a couple of truck-loads of them in the next street — and they were testing some more window-panes with their boots. Cautiously deciding to go another way, I was just about to turn back when I heard a voice I half-recognized.

‘Get out of here, you Jewish bastards,’ the young man yelled.

It was Bruno Stahlecker’s fourteen-year-old son Heinrich, dressed up in the uniform of the motorized Hitler Youth. I caught sight of him just as he hurled a large stone through another shop window. He laughed delightedly at his own handiwork and said: ‘Fucking Jews.’ Looking around for the approval of his young comrades he saw me instead.

As I walked over to him I thought of all the things I would have said to him if I had been his father, but when I was close to him, I smiled. I felt more like giving him a good jaw-whistler with the back of my hand.

‘Hallo, Heinrich.’

His fine blue eyes looked at me with sullen suspicion.

‘I suppose you think you can tell me off,’ he said, ‘just because you were a friend of my father’s.’

‘Me? I don’t give a shit what you do.’

‘Oh? So what do you want?’

I shrugged and offered him a cigarette. He took one and I lit us both. Then I threw him the box of matches. ‘Here,’ I said, ‘you might need these tonight. Maybe you could try the Jewish Hospital.’

‘See? You are going to give me a lecture.’

‘On the contrary. I came to tell you that I found the men who murdered your father.’