His mother wrote to say that Anton’s father despaired of the boy ever making something of himself and she was beginning to feel the same way herself. He put the letter aside.

‘I am a superfluous man,’ he told Friedrich, as they drank white wine at a table in the courtyard.

‘Have you been reading Pushkin again?’

‘No, I came to that conclusion all by myself. I’ve always found it hard to believe that there was any space for me in this world. Anything with my name on it.’

Meanwhile at night in his small room, Anton tried to map out a life that didn’t include blood-sausage or the opposite sex. While he waited for another magazine commission, he paid his rent by tutoring the children of rich families in mathematics, French or English; the work enabled him to leave Spittelberg and travel to more pleasant parts of the city.

Among his pupils was a boy called Erich, whose family occupied the entire first floor of a building in Döbling, a wealthy area that backed onto woods and vineyards. Once a week, long after Anton had graduated from the university, he caught a tram there and was let in by the porter. He ran past the doors of the lift, up the curved stone steps two at a time, his feet soundless on the crimson runner, rang the bell and waited for the maid to open it.

On one visit, in the spring of 1913, Anton was waiting in the drawing room, breathing a little heavily from his sprint upstairs, when he heard a piano. At this time of the afternoon, he would have expected the tinkle of an exercise or bagatelle – something built on a pattern with a little flourish at the end, when the variation was complete. What he heard was a piece in which the chord changes seemed to follow no pattern. It was only after two or three minutes’ listening that they seemed to make sense. He went to the door of the music room and peered in to see who was producing these mournful sounds.

Behind the vase of cut flowers on the piano, he could see the head of a young woman, tilted downwards as she played. The light from the tall windows fell across the lid of the piano, but the player remained in shadow. It was neither Katrin, the elder sister, nor Birgit, the little one. The music gathered speed, then seemed to run out of steam – to drift away and meander. Anton ventured further into the room, but the pianist was concentrating too hard to look up. As he took a pace or two closer, he could see that she was not following a score and wondered if she might be improvising.

It occurred to him that he should avoid giving her a shock; the last thing this woman in her reverie would want was the sight of him staring at her. He began to retreat over the Turkish rug, but when his shoe touched the parquet, the wood let out a small creak and she looked up.