Unity Mitford, the stormtroopers' MÃ„dchen, the aristocratic English brat who became, in the years just before WW II, one of Hitler's most slavish groupies, is the subject of this biographical reconstruction. Pryce-Jones (his family was acquainted with her family) strings together the remembrances of some 200 people in England and Germany who knew the fourth and most notorious Mitford daughter. She was, everyone recalls, the complete exhibitionist; her vapid, overprivileged childhood made her adept at flaunting all standards, to the terror of parents and governesses. Anything to dispel the boredom of life at Swinbrook, the family's Edwardian manse. Nazism, when she discovered it, had the ultimate shock value to draw attention to Unity Valkyrie--the middle name proves out--and, encouraged by older sister Diana (soon-to-be wife of Oswald Mosley), Unity bedecked herself with swastikas and Jew-baited her way to Germany and the restaurant Osteria Bavaria. There, in the guise of an art student, she sat daily waiting for the Fuhrer, until he noticed her. They never made it to bed, but Hitler liked her blond Englishness and her cheek and, according to Albert Speer, ""It was a shock to Hitler when she shot herself. He felt responsible for her suicide."" Pryce-Jones' empathy for Unity is nil, and indeed, infatuated Nazism apart, she is a cruel snob--anything but engaging. Still, the Bright Young Thing and her expensive friends and doltish parents make a vivid display of the decaying Tory society that toyed with the racialism and swagger of the Third Reich as an antidote to its own torpor. PryceJones spins it out excessively and rather overdoes the moralizing. No matter. Unity in Britain and Germany bellowing ""Hell Hitler!"" arouses genuine, unsavory interest that extends beyond the family connection.