Boston p.i. Spenser--perennial student of crime and cooking- -seems to be minoring in sociology these days: in 1991's Pastime, the subtext was male rites of passage; in last year's Double Deuce, it was black youth-gangs; and here, in a new, very satisfying case, the backdrop is AIDS, dysfunctional families, and child abuse. Who literally hammered society belle Olivia Nelson into an early grave? That's the question posed to Spenser by the victim's husband, Boston brahmin Loudon Tripp, who's hired the p.i. to back up the cops' hunt for the killer. But a new question soon arises: Who was Olivia Nelson, anyway? Looking for clues, Spenser travels to sleepy Alton, Georgia, where he visits the victim's senile father and learns through the man's lifelong black valet that Loudon's dead wife looked like--but wasn't--the real Olivia, who's living in Africa. Trouble brews when Alton cops and two thugs connected to a boozing, wenching US senator from Massachusetts (not named Ted Kennedy) strongarm the p.i.--who's saved from a bad beating when series' regular Martin Quirk, of Boston Homicide, rides to the rescue (Spenser's usual sidekick, Hawk, puts in only a cameo, though longtime lover Susan offers smart banter throughout). Back north, Spenser, working with a gay cop whose lover is dying of AIDS, confronts the senator, who admits to interfering with the case in order to cover up his affair with "Olivia." Spenser tattles to Loudon and his children, who turn out to be walking bundles of denial who'll accept neither "Olivia's" infidelity nor Loudon's incipient bankruptcy. A further turn brings the p.i. back to Georgia for unsurprising but trim revelations about the real identity of the dead woman--and her killer. With more mystery than most Spenser tales, and with the emphasis on sins of the soul, this is Parker as Chandler--and very well done.