Seventeen years after her mother, Dr. Cass Shelley, was stoned to death by an angry mob in Dayborn (La.), Kathy Mallory, who fled the scene to become a New York street kid and, eventually, an NYPD sergeant, is back to find out who provoked the mob and what became of her mother's corpse. Since Mallory is Mallory, she's in town less than an hour on All Saints' Day when Ira Wooley, an autistic savant who was the world's most unreliable witness to the killing, has his hands savagely wounded; Deputy Travis, who's never told everything he knows about the killing, has his chance to talk cut off by a massive stroke; Babe Laurie, the revivalist who'd be a leading suspect if ancient cases had suspects, has been murdered; and Mallory is sitting in the pokey, thumbing her nose at dogged Sheriff Tom Jessop and lecturing acting deputy Lilith Beaudare about how to stand up to her boss. Mallory's loyal friend Charles Butler, following her down from the city with the idea of helping her out, naturally remains a consistent two leaps behind her, though he does get to spend time with some flavorsome locals--manly spinster Augusta Trebec, mute sculptor Henry Roth, enterprising innkeeper Betty Hale (who's turned the stoning into something of a local holiday), and the rest of the equally nasty Laurie clan- -en route to a dizzyingly complicated windup involving spiritualism, child abuse, and good old-fashioned greed. O'Connell (Killing Critics, 1996, etc.) adroitly borrows P.D. James's trick of working the frontier where homicide shades over into the routine of sudden death. But Mallory's fans will be disappointed by the supporting role she's elbowed into here.