The Good Man - Gabriel Valjan

In a story that is Graham Greene's Third Man meets The Quiet American, it is 1948, and Vienna is the unlikeliest city for the birth of an intelligence agency. The city simmers with unrest. There are refugees fleeing Communism, displaced and stateless survivors of Nazi terrors waiting for visas to Palestine, and war criminals who have escaped justice. 

Jack Marshall manages the Company in a city divided between Britain, France, Russia, and the United States. Assigned Nazis to interview, Jack must determine who on his list can help the U.S. beat the Soviets in the race for atomic technology. 

Jack does well until someone on his list is found dead, a member of his team disappears, and a bureaucrat from the US visits to evaluate Jack's office. 

It is Jack, his trusted friend Walker, and Leslie, the most experienced spy in the office, against a killer. They find themselves in a world that is ambiguous and corrupt, surrounded by enemies and unexpected allies.