The central task of the collaborating biographer is to become as much as possible the person whose story is being told. To toss yourself away and inhale the realities of another person, another time. That is what happened to Susan Dworkin when she was working with Edith Hahn Beer, the woman whose astonishing escape from the Holocaust is the true story of Dworkin’s New York Times best seller “The Nazi Officer’s Wife.” Said Dworkin: “How did she find the courage to live as a U-Boat, hiding in plain sight in the Third Reich? How did she find the courage to trust a man who wore the uniform of the enemy? Identifying with Edith’s struggle was the true work of writing this book.”