It all seemed horrifyingly plausible: I couldn’t think how else she could have known about the operation. And if I was right, Father was almost certainly dead, and they would soon be hunting me. They would probably be waiting for me at the farmhouse, in fact.

I slowed down, and started walking in the other direction. Father’s letter to me had still been firmly sealed, and I guessed Anna had not dared open it for fear of losing my trust early on. The drop, then. I headed for it at once, and left a message that Anna Maleva, a nurse in the Red Cross hospital in Lübeck, was an NKVD agent, and knew about Sacrosanct.

A few hours later, I was holed up in a cabin halfway up the mountains, shivering in a wooden cot in the dark. Father had come across the place one day when we had been tramping across the Zone looking for clues. It had been used before the war by local mountaineers as a resting stop on their way to higher climes. Later, the Hitler Youth had taken it over for their excursions, and there were still signs of their occupation, from the insignia above the entrance to graffiti they had carved on the walls: the same sort of obscene phrases and drawings teenage boys make all over the world, for the most part, but disturbing nonetheless. I had immediately thought of the place, because it was well away from the main paths and still within easy walking distance of the nearest town if I needed food. There were no amenities for cooking, or anything else, and it was a lot less comfortable now than it had been during July, when we had come across it. But it was shelter.

I had placed my clothes in one of the cots for padding and tried to sleep as soon as I had reached it. But it was no use. Although still seething over Anna’s betrayal, I couldn’t shake the feeling that I had missed something in her allegations against Father, something in the tone of them. As daylight began to seep through the wooden slats of the walls, I finally realized what it was: despite trying to resist it, part of me could not help recognizing the ring of truth. He had been a fascist before the war, and was ardently, even fanatically, anti-Communist. And even if the Ukrainians had been guilty of the most horrendous crimes, we had nevertheless murdered them - did it make any difference in what cause? But the thing that kept pushing to the front of my mind was Father’s obsession for protecting the operation at all costs: his insistence that nobody could ever learn of it.

Had I just signed Anna’s death warrant?