When she and Rudolf had completed whatever it was they were setting off to do, she would move out of his apartment. And then her life would either be with Anton or she would live alone, as she had done before, but knowing better this time.

They were walking by the canal and her footsteps were light. The wind was funnelled down the path between the railway track and the water, through the leafless birch trees, and Lena had to wrap her coat tight across her as they pressed on through half-rural suburbs, before they came into the southern parts of Döbling.

When they arrived, after an hour and a half’s fast walking, they found the Karl Marx-Hof like a town of its own within the outer limits of the city, its walls the length of several streets, painted in dusty apricot, pitted with identical windows.

‘How on earth are we going to find Niklas?’ said Lena.

‘Follow me.’

They went beneath an arch into a courtyard the size of a village and Rudolf found an office where he began his search. Lena watched in awe. It was as if this moment, which to her was nothing but a cold and rather fearful void, was all that Rudolf had ever wanted from his life. It took them until late in the evening to find the building and the staircase, though Rudolf’s belief never flagged.

The corridor, lit by candles in the absence of electric light, was full of people, some of whom Lena recognised from Rebirth meetings. The tenants and their families had shared their rooms with hundreds of the Schutzbund and its supporters. In the small kitchens, teams of people worked to provide soup or sausages, while the ground-floor bakeries were emptied of their supplies.

They’d found Niklas in an end apartment that faced out over the main road. He was surrounded by young men drinking and smoking. One of them was playing an accordion, which, with the candles, gave it the feeling of an amateur nightclub.

Lena found herself fascinated by the apartments, comparing them to the rooms she had lived in as a child, where the basin was behind a curtain in the corner. But here there were water closets and separate kitchens and downstairs all kinds of shops. On the other hand, there was no wharf to watch and no sound of a riverboat’s deep engine.

No one seemed to be in charge. Niklas and three or four others tried to exert control, standing on chairs and shouting. Rudolf managed to gather most of the Rebirth people down to his end of the corridor and organise a food supply.

Looking through a small back window onto the expanse of courtyard, Lena could see that many other buildings of the Karl Marx-Hof were occupied and those who had not been able to find space were lighting bonfires outside to keep warm, singing workers’ songs. Their efforts looked fragile, and Lena found a sadness passing over her.

The talk inside was about arms, and who had them. It seemed there were some rifles in another building, rescued from a Schutzbund headquarters. There were rumours of grenades and machine guns as well, but no one seemed to know where they were.