Having borrowed money from Friedrich, he left a note for ‘Mlle Delphine’ on his next visit to Döbling. He was anxious about what concert to book because he knew so little about music; he remembered her dismissal of Richard Strauss, whom he personally, until then, had rather admired. There seemed to be nothing on offer by Mussorgsky, but in a small theatre he found a programme that featured works by Mahler and Schoenberg and felt confident she couldn’t dislike both. Mahler was a god of Vienna, once its youngest prodigy, and as for Schoenberg … Anton hadn’t heard his work performed, but in the window of a gallery had seen his self-portrait in green and thought his music must at least be better than his painting.

‘Dear Herr Heideck,’ came the reply to his lodgings, ‘it is kind of you to invite Katrin and me to the concert. Katrin’s father has given his permission and will accompany us to the concert hall, where we can meet in the foyer ten minutes before the performance begins. With kind regards, Delphine Fourmentier.’

Anton scribbled back, ‘Dear Mademoiselle, I should be honoured if you and Katrin would join me for dinner afterwards. I would of course arrange for a cab to take you home immediately afterwards.’ He had sealed and addressed it before it struck him that both sentences ended with the same word.

Delphine replied in French: ‘Cher Monsieur, On serait ravi de diner avec vous après et de profiter du fiacre après … DF’. ‘We would be delighted to dine with you afterwards and to take the cab home afterwards.’

Through gritted teeth, Anton persuaded himself that the teasing was not dismissive but playful – perhaps even flirtatious. When the day arrived he dressed in his best suit, his only suit, and made his way to the concert hall near the hospital in the ninth district. It seated only 300 people, though the stage was large enough to accommodate a full orchestra. The early arrivals in the foyer were different from the crowd he’d seen on the steps of the Opera House; there were not so many furs or top hats and most of them had the look of people who had had to rush from work.

Katrin’s father appeared in the swing doors and delivered his two charges to Anton with a threatening smile. Anton adopted the voice he used to editors on the telephone, blasé yet reliable, as he confirmed the arrangements for ‘afterwards’ and escorted Katrin and Delphine up the carpeted stairs, running his fingers up the dustless handrail.

As he settled himself between the two young women in their cheap seats, it occurred to Anton that he barely knew either of them. Yet here they were, Delphine in a dark green dress with black brocade and black shoes peeping out from underneath, Katrin in a white frock with a yellow ribbon in her hair, their knees an inch or so away from his, their arms sharing a rest with his, their breath warm on his cheek as they chatted about how the orchestra would manage to squeeze onto the stage and what little Erich had said yesterday … Here they all were at his bidding.