From British newspaper-reporter Marnham (So Far From God, 1985; Lourdes, 1981; etc.), a rather humdrum account of a murder that purportedly rocked London's aristo world more than a decade ago. On the night of November 7, 1974, Mrs. Sandra Rivett, a nanny in the household of John Bingham, Lord Lucan, was bludgeoned to death in the basement of her employer's home. In addition, Lady Lucan, recently separated from her husband, was attacked, though she managed to elude her assailant and ran screaming into the Belgravia night. It was Lord Lucan, his wife asserted, who, mistaking Rivett for his wife, had wielded the murder weapon. Then realizing his error, he attacked her when she came to investigate. An inquest later agreed with Lady Lucan's story. Meanwhile, Lucan himself, a remarkably unsuccessful frequenter of the London gambling clubs, had disappeared after making a couple of phone calls and dropping some notes to friends. In these he claimed that while passing the house he spotted a stranger attacking his wife and, quite naturally, intervened. (He had been living in his own digs since the separation.) He added he was ""going to lie doggo a bit."" He has not been seen since (suicide? Costa Rica?). Marnham has more than true-crime writing on his mind, however. His intention is to expose how the ""old boy"" network of London's postwar aristocrats attempted to shield Lucan, and acted as if they were above the law. Much of the book is taken up with the particulars of a trial in which one of these privileged types, Sir James Goldsmith, sued Marnham and the editor of Private Eye-for which Marnham had written an exposÃ‰ the case and gotten some of his facts wrong--for criminal libel. The ins and outs of British libel laws are explored in great detail, and there are implications of skulduggery in high places. It's all pretty esoteric and uninvolving, for readers on this side of the Atlantic, at least.