As D-Day approaches, Kampfgeschwader 200 prepares a massive Operation Ulysses attack on Britain--KG 200, the brigade of secret Nazi pilots who, equipped with American accents and identities, fly captured Allied planes into enemy territory, the perfect disguise for dropping spies and bombs. But, before the operation can begin, top KG-200 flier Rolf Warnow crashes in England, and, though they see through his American cover, the Allies allow Roll to steal an RAF plane and fly across the channel, followed by a young Anglo-American air-warfare duo. Their ground-and-sky trail leads to Norway (via the Resistance), to the remote mountain lake where KG 200 hatches its schemes. And, returning to England with a provocative clutch of clues, they figure out Operation Ulysses well enough to be ready for action when a squadron of American-looking B-17s come zeroing in on Big Ben. Having unearthed distinct but sketchy historical evidence of KG 200's existence, Gilman & Clive have made a reasonably solid fiction of it, humanizing the rather cumbersome aeronautical data with two familiar romance/conflicts: the terribly proper triangle formed by the Englishman, the American, and the Englishman's wife; and the dilemma of London double-agent Hannah, who helps her beloved Rolf to steal a plane but is later ordered to lure him to his air-battle death. A bit stodgy, a mite predictable--but prime goods for readers with a predilection for flying objects or military maneuvers. . . and sturdily efficient for everybody else.