From what Wolfgang Steiner could gather, his son was better behaved in Paris, but as a Gestapo agent he was useless, failing to solve any of his own cases and annoying colleagues by muscling in on theirs and trying to take the credit for them. One task entrusted to him was to recruit a network of informers; he was given funds to help him with that, but as far as his bosses could tell, he spent all the money in the brothels and bars around Boulevard de Clichy. Prostitutes and their pimps, he was told, made notoriously unreliable informers.

Matters reached a nadir when a resistance cell in Dijon was broken and a British agent arrested. Friedrich hurried to the city, where he insisted on conducting the interrogation of the British woman. He raped her so brutally she had to be taken to the prison infirmary, from where he took her out and shot her dead. What most bothered the Gestapo was that he’d failed to extract any useful intelligence from her.

It was around this time that Wolfgang discovered his son had a nickname – das Frettchen – which he apparently revelled in. He was sure the nickname was not meant to be as flattering as the young man clearly thought it was.

Friedrich even used it to introduce himself when he was back in Berlin. The name accompanied him to his next posting, in Amsterdam: the Netherlands seemed to be run by Austrians, and Wolfgang assured them he was close enough to be able to keep an eye on his son there. Amsterdam, he told Friedrich, was his very last chance. He had no more favours left to call on.

This turned out to be not entirely true. Once again, his son’s heavy-handedness led to the death of a British agent, in Enschede. But by now, Wolfgang’s star had risen high in Berlin: his network of contacts and his quiet influence was almost unrivalled, and he used every scrap of influence he could muster to stop his son being thrown out of the Gestapo. He agreed to a transfer somewhere so remote he’d had to look it up on the map. Surely even Friedrich couldn’t cause too much trouble there.

One of the symptoms of Wolfgang Steiner’s low mood was a pervasive pessimism and a propensity to worry all the time. As the war went on, he began to see this as a blessing: it was as if he finally had something genuine to worry about so he no longer had to worry about being worried. This didn’t mean his anxiety was unfounded, but it did mean he could be realistic. While most of Berlin struggled to contemplate the possibility of defeat, for Wolfgang Steiner it was something he’d long expected and indeed prepared for.

After the defeat at Stalingrad in February 1943, he had no doubt Germany would lose the war, though this was a sentiment he never voiced to any other person. From that moment he began to prepare for defeat and do everything he could to ensure his own survival. His innate pessimism ensured he had no intention whatsoever of hanging around Berlin. As he saw it, he couldn’t be accused of desertion: he’d wait until the battle for the city was all but lost. He was quite clear in his own mind that he would do more good for the Reich by leaving rather than remaining like some obliging fool to be killed or arrested by the Russians.