United States Army Lt. Col. Spencer Fleming becomes military attaché to Berlin. It is 1933 and Adolf Hitler has just become German chancellor. Germany now comes under rule of the Nazi Party. Fleming's distinguished career in military intelligence since 1915 uniquely qualifies him for this sensitive assignment.

Unlike most other large nations, the United States has no foreign intelligence service. Since WWI, America reverts to an isolationist view of European political turmoil. Foreign policy advisors close to President Roosevelt however become concerned that Adolf Hitler might soon lead Germany into another European war. Fleming becomes America's only official spy in pre-WWII Nazi Germany.