Dr Wertheimer had been right about the obsessive record keeping of the Nazi medical establishment. There were hundreds of names, spread out across the whole country. Every child had its accompanying set of vital statistics – name, age, address, names and occupations of parents. The reason for their hospitalization came next. Most common was ‘mental retardation’, closely followed by ‘physical handicap’. But some of the explanations for removing children from their families were profoundly chilling. ‘Congenital laziness.’ ‘Anti-social behaviour.’ ‘Racially contaminated.’

What must it have been like for the parents of such children, having to stand by while their offspring were dragged from them, knowing that to protest would be to bring retribution crashing down on their own heads without any prospect of saving their child? They must, he thought, have entered a state of denial that would have destroyed them emotionally and psychologically. No wonder post-war generations of Germans didn’t want to be confronted with what had been done to their own children with their apparent consent.

At least the profoundly handicapped among the children would have been spared any real understanding of what was happening to them. But for the others, watching as their fellow inmates perished around them, daily life must have shrunk to the pinprick of relief when another day dawned and their eyes were open to see it.

The fate of many of the children was listed very simply. ‘Treated with injections of experimental drugs. Failed to respond.’ Followed by the date and time of death. It was code for euthanasia, that much was obvious. This was a rare example of a point where the arrogance of the regime had faltered. Even though they were convinced they would never be called to account for what had been done to these children in the name of Aryan purity, they’d felt the need for euphemism here.

That didn’t mean there was much residual respect for the innocence of their victims, however. The destiny of other children was catalogued in brief terms that left Tony feeling ashamed to belong to the medical profession. Some had died in agony after being injected in the eyes in a series of experiments relating to eye colour. Others had been subjected to research into sleep cycles that had driven them mad. The list went on, sometimes with references to scientific papers where the results could be seen.

And no one had been punished for this. Worse, there were cases where a tacit deal had been done between the Allies and the defeated Nazis. Research conclusions would become the property of the victors in return for the silence of the perpetrators.