Hitler's Spy Chief (The Wilhelm Canaris Mystery)

'This book describes, in fascinating detail, the shady and complex workings of the international intelligence world, and the amazing ways in which Admiral Canaris tried to subvert Hitler, while apparently serving loyally.'

Wilhelm Canaris was appointed by Hitler to head the Abwehr (the German secret service) eighteen months after the Nazis came to power. But Canaris turned against the Fuhrer and the Nazi regime, believing that Hitler would start a war Germany could not win. In 1938 he was involved in an attempted coup, undermined by British Prime Minister Neville Chamberlain. In 1940 he sabotaged the German plan to invade England, and fed General Franco vital information that helped him keep Spain out of the war. For years he played a dangerous double game, desperately trying to keep one step ahead of the Gestapo. The SS chief, Heinrich Himmler, became suspicious of the Abwehr and by 1944, when Abwehr personnel were involved in the attempted assassination of Hitler, he had the evidence to arrest Canaris himself. 

Canaris was executed a few weeks before the end of the war.