Mildred Harnack was twenty-six and living in Germany when she witnessed the meteoric rise of the Nazi party. When the Second World War began, she became a spy, couriering top-secret intelligence to the Allies. In this work of non-fiction, Harnack's great-great-niece Rebecca Donner draws on extensive archival research, fusing elements of biography, political thriller and scholarly detective story. The true story of the woman at the heart of the German resistance to Hitler.