The screenplay written by Michael Wilson was based on the 1950 book Operation Cicero (original German: Der Fall Cicero) by Ludwig Carl Moyzisch, Nazi commercial attaché at the German embassy in Ankara, Turkey (1943–44).
James Mason plays the spy on a mission, darkly manoeuvring around in in ambience of espionage rather well, with his dark and sneaking ways, selling big secrets to some big Nazis.
Fabulous and famous, the spy code-named Cicero was one of the biggest names of World War II. The resulting drama film about the trusted but hugely amoral Albanian valet who had superb access to British secrets, was thrilling and cerebral and different enough to be nominated for two Academy Awards: Best Director for Mankiewicz and Best Screenplay for Wilson.