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.

He is the oldest in his convoy, but not the oldest of all. The names, hailing from Algiers, Budapest, Salonika, Karlsruhe, Lyon, Kishinev and Kiev include children and octogenarians. One, Betty Ruben, from Altmark, dies at the camp in Récébédou in her ninetieth year. Another was born in 1849. The birthplaces of the Mittelsteins, scattered across Europe, track the spread of the family like tree rings: Novo Radomsk, Paris, London, Paris, Nantes.

They are recorded among the 76,000 names listed in Serge Klarsfeld’s Mémorial de la déportation des Juifs de France, a kind of compendium of secret books, of lives that might have turned out otherwise.

NOTOWICZ, NIKOLAI 13.06.58 KERCH.

The mind recoils from the name in print. The record is terse. Upon arrival at Auschwitz on 23 December, 210 men were selected to receive the identification numbers 173708 to 173917 as well as 61 women (75340 to 75400). 1229 people were gassed immediately.

A tale so familiar and so strange. Sidings at dawn. Sealed stock cars opening with a rush of warmth and human smells. Guards in grey overcoats. Leafless trees. Laughter and lamplight from the windows of its headquarters. A gramophone playing ‘Stille Nacht’, the simplest and sweetest of carols, over a landscape that beggars imagination. An SS officer assigning life and death with the most casual gestures. There’s no way a man in his eighties would survive the sorting. Notovitch is getting ground up in the implacable machinery that he tried to sabotage. But the enormity of what’s happening is a terrible vindication of his gospel: if this is possible, surely all things are possible?