Mitka's Secret by Steven W. Brallier

The remarkable life story of Mitka Kalinski, who survived seven years of enslavement—while still a child—to a Nazi officer during and after World War II
Mitka Kalinski had never revealed his past to anyone. Not even to his wife or his four children.
But in 1981, three decades after it had all ended, Mitka finally broke his silence about the horrors he had endured during the Holocaust and in the years immediately afterward: not only German concentration camps and sadistic medical experiments but also seven years of enslavement in the household of a Nazi officer, "Iron" Gustav Dörr.
Having been orphaned before the war, Mitka did not know his origins or even his name. Torture, slavery, and a false name stripped him of his identity entirely. Thus, when he immigrated to the United States in 1951, Mitka seized the opportunity to bury his past and forge a new life. He lived the American life in all its fullness and moved to Nevada with his beloved wife, Adrienne, and their children. But the secret he carried became an increasingly heavy burden, preventing wholeness and healing.
This is Mitka's account of facing the past, confronting his captors, connecting with lost relatives, and finding peace in the rediscovery of his origins. For Mitka, this also meant reclaiming his Jewish heritage—a journey that gave him a new sense of purpose and freedom from the lingering effects of trauma that had filled his life to that point. By the end, Mitka's Secret is less a story of survival and more one of redemption and transformation—from hidden suffering to abundant joy.