Karl Gönner was a Nazi, and his family didn't ask a lot of questions about that time in his life. But after his death, they came to find out, in a most unexpected way, that he'd protected villagers in occupied France against abuse by the Nazi regime. In this episode of Constant Wonder, a family discovers that their history is more inspiring than they'd ever suspected.

Guest: Burkhard Bilger, author of "Fatherland: A Memoir of War, Conscience, and Family Secrets" and staff writer at "The New Yorker"