The greatest secret of the Second World War has remained a mystery for the last 80 years: a Jewish Communist, Sandor Rado, led a spy network that proved essential to the victory of Allied Forces. Rado received details of strictly confidential strategies from the highest echelons of the Nazi State through Rudolf Roessler, a dedicated anti-Nazi he'd only known as code name "Lucy." Aided by key German industry leaders, Roessler transmitted timely information from high-ranking collaborators within the German army headquarters. Despite their achievement, Rado, Roessler and their sources remained unacknowledged heroes until today. Thanks to the recent declassification of secret archives, we are now able to step behind the scenes of this incredible story.