On Bloody Sunday : a new history of the day and its aftermath by those who were there
Julieann Campbell
Harro Schulze-Boysen had already shed blood in the fight against Nazism by the time he and Libertas Haas-Heye began their whirlwind romance. She joined the cause, and soon the two lovers were leading a network of antifascists that stretched across Berlin's bohemian underworld. Harro himself infiltrated German intelligence and began funnelling Nazi battle plans to the Allies, including the details of Hitler's surprise attack on the Soviet Union.