Shades of Arthur Conan Doyle's ``Silver Blaze''! When the sun comes up on North Carolina's February Farms, there are two casualties: dead trainer Wally Hempstead and premier show-jumper Russian Caviar, a.k.a. Ruskie, who's to be destroyed after the beating he's taken from Hempstead's crowbar. As in Sherlock Holmes, the human victim is several notches below the horse he attacked. But first-novelist Jaffe's Natalie Gold, hungry fashion-reporter for the Charlotte Commercial Appeal, finds other riders who accuse him of wholesale blackmail and equinicide, and nobody expresses anything but satisfaction that he's dead. Sadly, he's followed by two more human (and deeply mourned) victims before Nattietaking time out from her romance with married police detective Tony Odom and her far more satisfying relationship with her own jumper, Brenda Starrthreshes out the clever red herrings to identify a well-hidden killer whose gravest flaw is being not especially interesting. Nattie herself, however, more than offsets the killer's blandness: bright, lively, self-consciously a Philadelphia yenta, she's a most appealing guide to a Carolina show-jumping circuit delightfully remote from the racetracks of Dick Francis and Bill Shoemaker.