As she swerved after them down a side street that had a large arrow marked ‘Public Air-raid Shelter’, the city’s outer ring of anti-aircraft guns boomed into life. By the time she abandoned her bike at the shelter’s entrance, the second ring of anti-aircraft guns was thundering.

Clutching her precious bag of bottles to her chest she clattered down narrow metal steps, knowing she had at least a two-hour hell of claustrophobia ahead of her.

From outside the shelter came a long screaming whistle and then a terrific, rocking explosion. The blast sent her flying to her knees, her arms still around her bag. An elderly woman fell against her.

‘Dear God,’ the woman said as they helped each other stagger to their feet. ‘They must be bombing directly above us! What is left in this part of the city that they can destroy?’

As far as Lotti was concerned, the answer was nothing, but she couldn’t say so, because the noise was now so intense the woman wouldn’t have been able to hear her. Bomb after bomb was raining down, explosion after explosion shaking the shelter so that it rocked like a ship at sea.

Weak-kneed, she squeezed onto one of the crowded benches, praying that her mother’s apartment hadn’t been hit, praying that Ilse was safe, praying that the British and the Americans would speedily cross the Rhine and then the Elbe and that the nightmare they had been enduring for over five years would at last come to an end.

Hester stood in the garden of the Unter den Linden mansion, watching as hundreds of heavy bombers flew across the outskirts of the city towards its centre. They looked to be flying at a lower altitude than normal and in closer formation, and all of them seemed impervious to the anti-aircraft fire exploding around them. Had they flown in over Spandau? Had they already dropped bombs on the factories there? Had Claus’s factory been bombed? They were coming in waves, the sky black with them.

With her mouth dry with fear for Claus’s safety and for the safety of all the Jewish and Russian women working for him, she spun on her heel, running back into the house, reaching the entrance to the cellar only as the first bombs began to fall.

Whenever there was a raid through the day she was always alone, for Claus would be either at the factory or in the Ruhr, and shelter in a public air-raid shelter was impossible for her. The SS had grown even more maniacal as the war had gone from bad to worse and the slightest suspicion that she was a Jewess would be enough to ensure swift incarceration again at Sachsenhausen—and the barbarism at Sachsenhausen had plummeted to a depth hard for any sane mind to grasp.

‘It’s now not only a death camp because of starvation and torture and indiscriminate killings, it’s an official death camp,’ Claus had said to her not long after he had successfully established a camp for his Russian workers inside his factory’s precincts. ‘I’ve had the information from Göring himself.’