Dovidl’s Hebrew, barely functional at his barmitzvah, picked up fluency and speed under continuous usage. His Yiddish, forgotten since infancy, returned intact. His appetite for knowledge was ravenous, overwhelming several of his teachers. They referred his questions, some heretical, to the Young Rebbe, who knew all but did not always vouchsafe an answer. The Rebbe was their repository of all knowledge but, like Josef in Egypt, he eked it out according to need, saving enough in his granary for future famine. Dovidl felt sure that, if he approached him with a musical problem, the Rebbe, with his fine ear and brilliant mind, would resolve it by force of logic without being able to read a score. And if, to master the issue, he needed to decipher notes on the page, he would learn to read music in an hour from a printed tutor. No musician that Dovidl had ever heard could crack a theological conundrum or speak meaningfully about the origins of the universe. The Rebbe, he reckoned, had a wealth of information and an analytical ability that was superior to anything he had encountered. The very qualities he had once admired in me were, once more, outshone.

One morning, as Spielman was coaching him in the Aramaic vernacular of the mystic Kabalah, the Young Rebbe came over to their synagogue lectern. Both rose.

‘It may, forgive me,’ said the Rebbe, ‘be necessary to transfer the guest to a safer place.’ He held in his trembling hand a letter from the president of the Board of Deputies of British Jews, alerting the Medzhiner community to their concern for a missing Polish-Jewish violinist and asking for any information to be conveyed, through the Board, to the Metropolitan Police. There was nothing to connect the Medzhiners to the absent musician, but the embossed letterhead made the Rebbe uneasy and the mention of police aggravated his anxiety. ‘Away from London,’ said the Rebbe. ‘In the north of the country, there is a new yeshiva with forty students. All of them have dark beards and long capotas. A new person will not be noticed there.’

‘How long shall I stay?’ said Dovidl, marvelling at his own will-lessness.

‘A month, a year, as long as you like,’ Spielman assured him. ‘Then you will come back a talmid chochem, a learned man, and we will find you a shidduch, a nice girl to marry.’

‘When do I leave?’ said Dovidl.

‘There is a vehicle outside,’ said the Young Rebbe, extending a skeletal hand in benediction. No blood seemed to pass through its veins as Dovidl bent to kiss it. It was, he sensed, another of those partings when he would never see the other person again.