The German Martin Schulse and the American Jew Max Eisenstein run a successful art gallery in the USA. In 1932, Schulse decides to return to Germany with his family. Eisenstein continues to manage the joint gallery in San Francisco. The two men stay in touch and exchange thoughts on professional and personal matters in their letters. Initially, it seems that their friendship is not suffering from the physical distance. However, Schulse, who initially viewed the political developments in Germany critically, gradually becomes an avowed Nazi. "Address Unknown," first published in 1938, is a book of unsettling relevance. Structured as a correspondence between a German and an American Jew during the months surrounding Hitler's rise to power, this masterpiece depicts the dramatic evolution.