‘What do you want me to do?’ Charlotte said on our doorstep. ‘Wear a hooped skirt and girdle? I won’t, Paul. That’s not me.’

‘Fine. Let’s just go.’

We walked quickly. The lit Advent wreaths did nothing to lift our mood. With the streetlamps giving not much more than a fizz, at least people might think she was a man, with the ironed-in creases of her trousers and her hat hiding her face. The air that night was wet and freezing. Around us people left the cinemas, blinking at the tumbling colours. People did not look us in the eye. Nobody wanted trouble. I put out my hand to Charlotte’s and though she took it there was little promise of her speaking to me. She didn’t like being told what to do – fine – but I just wanted her to be safe. It was not a crazy thing to want.

We arrived at the party almost silent. If Irmi noticed the chill between us, she didn’t let on. Her flat was stuffed with people. Candles lit the condensation on the windows so that the world outside was nothing more than diffused light. There were bottles of colourful alcohols – ambers, emeralds, rubies, all cold and beaded (Irmi had stolen them from the Kaiserhof) – and people were drinking from jars or glasses stamped with the hotel’s logo.

Charlotte went to find a drink. Irmi kissed me on either cheek, gave me a consoling smile, and handed me someone else’s glass. ‘Let me find Teddy. I want to introduce you.’ And then Irmi disappeared too.

She had been stiff with me when Charlotte and I had first arrived in Berlin; not surprisingly. I’d forgotten to reply to her letter; I’d only just got together with Charlotte and was at the height of my obsession; in short, I’d behaved badly. But Irmi, saint that she was, forgave me.

I looked around for someone I knew, but it was Kaspar who found me. Since Weimar he had failed to age, but he had got heavier. He looked sunburned. ‘However did you get that tan?’

He kissed me on both cheeks. ‘Artificial light treatment. Otherwise I look as if I’m made from paper.’

By his side was a tall woman with a big smile in not much of a dress. ‘It’s Berlin. It’s December. That’s how everyone looks,’ she said. She had a strong Russian accent, but then there were so many Russians in Berlin it almost went without remark.

‘Dacia, this is Paul Beckermann, an old friend of mine from the Bauhaus.’

‘How do you do?’ she said, looking elsewhere.

He leant toward me. ‘I’m going to marry this one, Paul. I know it.’ The warm air in the room made Kaspar’s face pulse brighter.