He reassures Anya. Father Gerasim will have proof of their baptisms and marriage. They will straighten this thing out: perhaps join Volchkov in Lyon while the unpleasantness subsides. He finds Gerasim in the vestry. The priest listens without expression and replies unhurriedly.

‘You’ve not been to church for a while,’ he says. ‘I have a proposal: I’ll find the paperwork that shows your parents are Orthodox believers from beyond the Urals, born east of the Pale, in the land where no Jew ever set foot. In return, you repudiate the lies in your book.’

How long has Gerasim been cooking up this plan? He’s an opponent of heresy, innovation and woolly thinking. The position of the Church is very clear: submit to tradition or take your chances on Judgement day. Religion is not a menu à la carte.

The old man blazes, suddenly young. ‘You whippersnapper! How dare you!’ Gerasim turns his back until he hears the door shut.

Upon reflection, Nicolas realises he must do as the priest asks. If he’s drawn a conclusion from his life, it’s that a human being is worth more than any mere idea. But now it’s too late.

On 7th June 1942, Parisian Jews are legally obliged to buy and wear the yellow six-pointed Star of David. They pay for it with clothing coupons. Jews are banned from public places and subject to curfew between 8 p.m. and 6 a.m.

On 16th July 1942, Anya and Nicolas are rounded up with 13,000 other Jews and confined to a velodrome on the outskirts of Paris. A single jury-rigged standpipe supplies dirty river water for washing and drinking. Anya contracts dysentery and is taken with Nicolas to the Rothschild Hospital on Rue Santerre.

He holds her hand at the end. She is gaunt, unrecognisable. There is no trace of the shiny, squirrel-bright girl he courted with all that torment and ambivalence five decades earlier, in another life, another century. He strokes her face.

‘Remember our wedding?’ she says.

He says he does.

‘Remember I called to you on the balcony? I thought you’d never come in. You were crying. It was our wedding night. Remember?’ She squeezes his hand. Her flesh is yellow, her fingers cold and dry.

‘Because I loved you so much,’ he says.

‘Really?’

‘Yes.’ There is a catch in his voice. She closes her eyes.

Thousands of the interned Jews are transported out of France, but Nicolas is briefly reprieved. He is transferred to Drancy, and carries his tiny cardboard suitcase into one of the modernist five-storey blocks that remind him a little of the blocky lines of Hemis. From the rooftop, beyond the barbed wire, he can see the dome of Sacré-Coeur in Montmartre.

One by one, convoys depart. There are seventy-eight in all. Number sixty-eight leaves from Drancy on 20th December 1943. The passenger list gives family names, first names, dates and places of birth.