Girl loves horse/girl loses horse--with a fresh, knotty twist. The Connecticut countryside is filling up, leaving narrator Kate few places to ride her high-strung thoroughbred Tracker--who thrives, however, as a mount for Kate's best friend Shelby, a serious horse-show competitor. And now Shelby's rah-rah father wants to buy Tracker for her. The story of the book is the story of Kate's decision--with flashbacks to Kate's lifelong love-affair with horses, Shelby's jealousy and sudden interest, and her natural flair for riding . . . which Kate doesn't begrudge her. What pains Kate is Tracker's growing attachment to Shelby, for whom he's just an appropriate mount, to be discarded (there are signs already) when she's ready for a still ""better"" horse. But on the other hand Kate's efforts to find places to ride Tracker end in a near-disaster--and with some prompting from two elderly deus-ex-machinas (the book's preeminent false note), she makes the painful decision to give him up. Hippie friend Larry (a lesser false note) concurs: previously anti-Shelby, he has to admit she and Tracker are quite a pair. Even with this sort of anti-romantic weighting, however, the story has sufficient tingle to leave readers puzzling the situation for themselves.