Hans Bernd Gisevius

Gustav-Adolf Timotheus Hans Bernd Gisevius was a German politician, Gestapo and Abwehr officer and diplomat during the Second World War. He was a member of the Military Resistance, who actively participated in the Oster Conspiracy and the 20 July Plot, being among the few survivors. A covert opponent of the Nazi regime, he also served as a liaison in Zürich between Allen Dulles, station chief for the American OSS, and the German Resistance forces in Germany. (Wikipedia)