Born in Milwaukee, Mildred Harnack was twenty-six when she enrolled in a PhD program in Germany and witnessed the rise of the Nazi party. In 1932, she began secret resistance meetings in her apartment, then became a spy. When the Gestapo caught her, she was beheaded. Historians identify Mildred Harnack as the only American in the leadership of the German resistance, yet her remarkable story has remained almost unknown. Here, Harnack's great-great-niece Rebecca Donner recreates her story from family documents.