Dr Wertheimer’s eyes lost their sparkle. ‘The ones who survived? They were treated like lab rats. Mostly they were kept down here, in a series of cells and dormitories. The staff called it the U-Boot – the submarine. No natural light, no sense of night and day. They did various experiments with sleep deprivation, altering the length of the perceived days and nights. They would allow a child to sleep for three hours, then wake it and say, “It’s morning, here’s your breakfast.” Two hours later, they would serve lunch. Two hours later, dinner. Then they would be told it was night and the lights would be turned off. Or else the days would be stretched out.’

‘This was supposed to be research, right?’ Tony asked, the tang of disgust in his throat. It never failed to appal him that members of his own profession could move so far from the avowed duty to help those entrusted to their care. There was something fright-eningly personal about this case, summoning as it did the images of a nightmare that had been created by men and women who must at some point have believed in the therapeutic possibilities of their work. That they could have been so readily corrupted from that ideal was frightening because it was a stark reminder of how thin the veneer of civilization truly was.

‘This was indeed supposed to be research,’ Dr Wertheimer agreed sadly. ‘It was supposed to help the generals decide how hard troops could be driven. Of course, it had no practical application whatsoever. It was simply the exercise of power over the weak. Doctors indulged their own whims, tested their own notions to destruction. We had a water torture cell here where they performed acts of unspeakable cruelty both physical and mental.’

‘Water torture?’ Tony’s interest was pricked.

‘We weren’t the only institution to have such a facility. Notoriously there was also one at the Hohenschönhausen prison in Berlin, but that was for adults. Here, the subjects were children and the intent was supposedly experiment rather than punishment or interrogation.’

‘Did they force water down the children’s throats at all?’ Tony asked.

Dr Wertheimer frowned at the floor. ‘Yes. They conducted several series of experiments to test physical resistance to this. Of course, many of the children died. It takes a surprisingly small amount of water to drown a child if you force water into their airway.’ She shook her head, as if willing the images away. They also used it in psychological experiments. ‘I don’t have the details of those, but they will be in the records somewhere.’

‘Would you be able to find them for me?’