Cave Brown has been on this trail for over 20 years and has brought to bear a wide variety of materials. Yet few of these are as novel or revealing as he tries to make out, and the result is still murky, even as a portrait of the head of Britain's wartime and immediate postwar secret service, and unhelpful on the tough questions that still surround that service. In the end Menzies emerges much the same as one might have thought before on the basis of such serious and incisive books as Christopher Andrews' Her Majesty's Secret Service: very spotty in his judgment of people and operations within his own secret intelligence bailiwick (notably in the Venlo Incident); effective in helping to get important prewar Polish and French help on the breaking of the Enigma code (and in devising security procedures for this crown jewel), but otherwise little involved in the brilliant Ultra success nominally under his command; above all, incredibly insensitive and class-ridden in his most devastating error, the failure to detect that Kim Philby was a Soviet spy. (On the last, the author produces and clings to a bizarre hypothesis convincingly rejected by Menzies' own associates.) The lay reader may find this book entertaining, if the salt shaker is kept handy. Serious students should treat it with special reserve.