‘Well, if you are sure, that would be very kind of you. I have had a bit of a shock.’ She picked up the box that lay at her feet, each one of which bulged over the top of its well-polished black walking shoe like a butcher’s thumb in a thimble. Her name was Frau Schmidt.

‘You’re a good sort, Herr Gunther,’ said Wilhelm.

‘Nonsense,’ I said, and so it was. There was no telling what information I might glean from the old woman about her late employers. I took the box from her hands. ‘Let me help you with that,’ I said. It was a suit-box, from Stechbarth’s, the official tailor to the services, and I had the idea that she might have been bringing it for the Pfarrs. I nodded silently at Wilhelm, and led the way to the car.

‘Neuenburger Strasse,’ I repeated as we drove off. ‘That’s off Lindenstrasse, isn’t it?’ She confirmed that it was, gave me some directions and was silent for a moment. Then she started weeping again.

‘What a terrible tragedy,’ she sobbed.

‘Yes, yes, it’s most unfortunate.’

I wondered how much Wilhelm had told her. The less the better, I thought, reasoning that the less shocked she was, at least at this stage, the more I would get out of her.

‘Are you a policeman?’ she asked.

‘I’m investigating the fire,’ I said evasively.

‘I’m sure you must be too busy to drive an old woman like me across Berlin. Why don’t you drop me on the other side of the bridge and I’ll walk the rest. I’m all right now, really I am.’

‘It’s no trouble. Anyway, I’d quite like to talk to you about the Pfarrs - that is, if it wouldn’t upset you.’ We crossed the Landwehr Canal and came onto Belle-Alliance Platz, in the centre of which rises the great Column of Peace. ‘You see, there will have to be an inquest, and it would help me if I knew as much about them as possible.’

‘Yes, well I don’t mind, if you think I can be of assistance,’ she said.

When we got to Neuenburger Strasse, I parked the car and followed the old woman up to the second floor of an apartment building that was several storeys high.