In the midst of bombing raids on Berlin, the Abwehr-the German Secret Service-- receives an anonymous letter describing in incredible detail top secrets of the German and Allied war plans. Claiming to be an embittered American, Robert Ballard produces a stream of top secret information from both sides of the conflict that can only come from the very highest levels. Embraced by the Abwehr, his extraordinary success in thwarting Allied attacks soon arouses the suspicions of the Gestapo. How can an foreigner be operating a massive spy ring right under their noses? Oskar Faulheim of the Gestapo discovers Ballard's infatuation with Sabina Pergolesi, a beautiful Italian widow. He quickly resettles her mother in a seedy pension next to the Ravensburg concentration camp. "Find out everything you can about your Herr Ballard, Faulheim warns Sabina, or she'll be moved into the camp-with you to quickly follow. If Ballard remains a mystery, Sabina Pergolesi is also not what she seems. When Ballard mentions they cannot return to America where he would be branded a traitor, she flees him in tears.