There can be nothing but huzzas for authors Dempster and Wood: in The Narrow Margin they have given us as clear, compact and microscopically close a reading of the Battle of Britain as anyone could want. Certainly the battle which marked the advent of controlled scientific warfare, the defense strategy still used today, must be considered one of the crucial events of our time. And the authors leave nothing out: the formation and expansion of the RAF, the Luftwaffe development with its Messerschmitt, the Fighter Command and its Spitfire; the rise of Nazi Intelligence, the brilliant uses of radar and antiaircraft, the ROC, the training of men, the detailing of missions; Churchill and his canniness, the deftness of Dowding, the grotesque inflexibility of Goring and Sperle- all of it's there, as tight and tense as a net. As for the battles themselves, they're divided into five phases, between 11 July and 30 October, and then set against a complete operational day-to-day diary. The maps and photographs are expert and the appendices include drawings of all bombers, commands and casualty numbers of both sides and listings of all targets attacked. Hitler's ""Luftkrieg gegen England"" quite unexpectedly gave his enemy their finest hour; Margin commemorates the event with startling scope and illumination. This may well prove a sleeper, so don't overlook it.