On a clear Autumn day in 1938, the Nazi flag was raised over Cardiff City Hall - a startling reminder of the respect, even admiration, that some in Wales felt towards Hitler. This story of political intrigue and espionage reveals how the Third Reich tried to exploit an ambivalence that stretched across the Welsh political spectrum. But ultimately the Germans' belief that they could recruit the Welsh to their cause would prove fatally damaging - not to Wales, but to the Nazis themselves.