The series is set in an alternate history in which Germany and Japan won World War II by the murder of Franklin D. Roosevelt in 1933. It revolves around SS undercover agent Joe Blake, the Jewish Frank Frink and his ex Juliana Crain, who in San Francisco gets a film role from her dying sister in which the Allies win the war, albeit only in 1947. Juliana wants to take that subversive film to the underground resistance in Colorado, but finds herself involved in a complex game of spies, double spies and triple spies around SS. leader Heydrich, the old Hitler, the Japanese secret police Kempeitai and the Japanese crown prince, who visits California.