When it comes to spy novels, no one is more erudite or elegant than Alan Furst, whose novels -- all set in the European theater of World War II are rich with both historical fact and brilliantly imagined circumstances.
The World at Night (Jean Casson Series #1)
The Spies of Warsaw
The Polish Officer
Kingdom of Shadows
Blood of Victory
Red Gold (Jean Casson Series #2)
The Foreign Correspondent