Two Czech patriots return to their homeland to assassinate notorious Nazi Reinhard Tristan Eugen Heydrich (7 March 1904 - 4 June 1942) was a high-ranking German SS and police official during the Nazi era and a principal architect of the Holocaust. He was chief of the Reich Security Main Office (including the Gestapo, Kripo, and SD). Many historians regard Heydrich as the darkest figure within the Nazi regime while Adolf Hitler described him as "the man with the iron heart".