The knowns, and some of the conjectural unknowns, in the life of Admiral Wilhelm Canaris, an enigmatic to elusive figure in espionage who served as Hitler's Chief of Intelligence for nine years, but who may have been a British agent as well. Charming, exacting, mistrustful, softspoken, Canaris became an Admiral during the first World War, but officially entered the Abwehr (Security Service) in 1935 of which he was later to become head. Here are the delicate to dubious military and diplomatic interchanges in which he figured; the occasions on which he sabotaged and betrayed German plans and proceedings, from the Munich pact to the proposed invasion of England and throughout the conduct of the war, until his deposition by Hitler in 1944, and his execution in 1945. An investigation which relies on fact-which has been difficult to isolate- rather than sensational speculation, this is a deliberate, detailed account by a former correspondent of the London News Chronicle. For the spy chaser.