I went into Birkenau and let myself be guided by instinct. I tried to forget everything I knew, I wanted to know what it felt like to step into this camp for the first time, knowing only its monstrous reputation. It was difficult, it was impossible, I knew too much, I had spent so much time studying this place I could have moved around it with my eyes closed, the map was burned onto my brain. I could have moved around like a diligent soldier, anxious to get from A to B to execute his orders promptly. I could retrace his footsteps, walk boldly as he did, wrapped up in a thick greatcoat against the blizzard: bringing a wounded worker from the infirmary to his work station; dragging some human wreck to Bunkers I and II where French Jews were gassed; picking up the daily productivity reports from one of the four ultra-modern complexes – the famous K II, III, IV and V, marvels of extermination designed, they say, by Himmler himself, to function both as gas chambers and crematoria – and dashing back with him to the SS Administrative Building, allowing myself a quick visit to the Kapos’ brothel to see the new arrivals or, out of morbid curiosity, peeking through the window of the experimental clinic run by Carl Clauberg, or the one run by the sinister doctor Josef Mengele, the Frankenstein of monozygotic twins; swinging by the laboratory where chemical engineers like my father – who, given he was an SS-Hauptsturmführer by then, was probably in charge – worked on their magic potions, their treatments for lice; everywhere in fact, except the baleful area of Block 11 where lunatics unlike any on earth experimented with tortures and methods of execution which were bizarre even in Auschwitz. I could just as easily move from the parade ground where the prisoners assembled at dawn and lead a group to wherever they were assigned to do forced labour.

I have learned to follow my father in my mind, I could have wandered around the Lager as though I had grown up here. There is not a single detail of his working day I have not imagined. Papa was a methodical man, regular as a metronome, he spent his whole life obsessed with timing things. Our life in Aïn Deb was regulated by his watch. While my childhood friends needed only a ray of sunshine, a sudden whim to go from place to place, there I was, champing at the bit, watching the big hand on the house clock, waiting for my fifteen minutes of freedom.