Not that their notes suggested the Oberst was up to anything. He lived in the officers’ quarters at the Luftwaffe base next to Tempelhof, from where he travelled to work before seven thirty most mornings, returning some twelve hours later. Outside of work he swam two or three times a week (mostly front crawl) or drank with colleagues in a bar near the Air Ministry. He was not a member of the Nazi Party and like so many Luftwaffe officers was not known to be political. His family were from Augsburg and contact with them appeared to be limited to a letter each way once a month, the language in them polite and formal, the subject matter inconsequential.

On the evening of Wednesday 2nd December, Oberst Albert Kampmann was followed after leaving work on Wilhelm Strasse. He didn’t go into one of his regular bars, nor did he catch a tram or the U-Bahn back to the airbase. Instead he took a particularly circuitous route, one that aroused the suspicions of even the Gestapo: north on Wilhelm Strasse to Unter den Linden, up and down Unter den Linden before picking up his pace quite considerably and hurrying down Friedrichstrasse, where they lost him for a few minutes, before eventually picking him up turning left into Leipziger Strasse. He was followed across Jerusalemer Strasse into Donhoff Strasse, where he disappeared again. They looked everywhere for him: the notebooks weren’t terribly explicit, but from as far as Frank could ascertain, it was a good ten minutes before they decided to look in a restaurant on Donhoff Strasse called Das Bayerischer Haus. One of the Gestapo officers had noted: We have reason to believe this could be a Bavarian restaurant.

They couldn’t see him downstairs, but a waiter told them there was a group of men in the private dining room upstairs. When they went up there, the room was empty. Unbelievably – though Kriminaldirektor Frank could actually believe it – it took them another five minutes to work out that there was a door concealed in the panelling, behind which was a staircase leading to the yard of a neighbouring building.

They searched the area and through what Frank reckoned was probably luck more than anything else, came across Oberst Kampmann further down Donhoff Strasse. They challenged him to stop; he refused and opened fire with his Mauser semi-automatic, hitting one of the Gestapo officers in the leg. Two of them returned fire with their sub-machine guns and Kampmann was mortally wounded. He was taken to the Charité hospital but never regained consciousness.