Paul’s job came with a modest flat several floors below the Kalinins’. Here he was to tutor Anton every morning, Monday to Friday. When it was time for Anton’s lesson, it was usually Darya who brought him down in the lift, before she went out to run errands, or, as the weather cooled, before she went nowhere at all, staying home to binge-watch Breaking Bad. He learned that she used to work selling TV advertising but had given up the job because she was away too often with Nikolai, accompanying him to the dacha near Tula (this was where he kept and rode his beloved horses) or on work trips further afield. ‘At least I have this one,’ she said brightly, tousling Anton’s hair. Belting her coat securely, she would run out to buy cigarettes, only ever paying cash so Nikolai wouldn’t know.

Paul did not meet Anton’s mother, but she was present by her absence. Her disease was almost lunar, the way it waxed and waned. It confounded her doctors and by extension Nikolai, who had a rationalist’s faith in medical science. Mrs Kalinin’s condition was frequently discussed, and there were times when it looked like she might take Anton back. Paul had to wonder what Darya made of this. She had an ex-husband too, but he was practically never mentioned. Paul knew only that he had fought in Chechnya; Darya would later say, in a comment he found shocking, that it would have been better if he had died there.

Paul’s focus was Anton; he tried to bring him out of his shell. His young student was placid. Not fast to learn, but willing. He liked the flash cards Paul used, he counted in English, and he grew better at stringing sentences together. Paul was surprised to find that he enjoyed the work. Not that anyone kept tabs on what he did. Paul saw less and less of Nikolai as the autumn went on, and whenever he did put his head through the door of the flat he had an embattled look. His divorce from Anton’s mother had gone halfway then stalled. Perhaps it was the lupus; perhaps he was under fire at work.