Born and raised in Milwaukee, Mildred Harnack was twenty-six when she enrolled in a PhD program in Berlin and witnessed the meteoric rise of the Nazi party. In 1932, she began holding secret meetings in her apartment - a small band of political activists that grew into the largest underground resistance group in Berlin.She helped Jews escape, plotted acts of sabotage and wrote leaflets denouncing Hitler's regime, slipping them into mailboxes, public restrooms, phone booths. When the first shots of the Second World War were fired, she became a spy, couriering top-secret intelligence to the Allies. On the eve of her escape to Sweden, she was ambushed by the Gestapo. At a Nazi military court, a panel of five judges sentenced her to six years at a concentration camp, but Hitler overruled the decision and ordered her execution. On 16 February 1943, she was strapped to a guillotine and beheaded.Historians identify Mildred Harnack as the only American in the leadership of the German Resistance, yet her remarkable story has remained almost unknown until now.

Fusing elements of biography, political thriller and scholarly detective story, Harnack's great-great-niece Rebecca Donner brilliantly interweaves family archives, original research, exclusive interviews with survivors, and a trove of declassified intelligence documents into a powerful, enthralling story, reconstructing the moral courage of an enigmatic woman nearly erased by history.