A nicely managed gift-gets-horse story--with individuated characters and some unexpected twists. Sarah (about eleven), her teacher Mom and writer Dad have just moved to a small Vermont farm; and Sarah, ""more than anything in the world,"" wants a horse. Enter shaggy, endearing, infuriating half-Morgan Barney, whose devoted owner Missy is now away at college. Can Sarah be trusted, her parents argue (openly, logically, non-acrimoniously), to care for Barney over the winter? ""Have you ever considered,"" Mom concludes, ""that having a horse might actually develop her sense of responsibility?"" So, with Missy's own hesitant, long-distance OK, Barney becomes Sarah's pro tem--and her troubles begin. Not only with the stubborn, independent, cagey Barney, but also with good friend Albert--hostile and derisive just when Sarah needs a fellow-rider's support. Albert (it turns out, not-discreditably) resents newcomer Sarah's getting Barney when their mutual friend Jill, from a large, impecunious family, can't have him. Indeed, motives here are always understandable, however unfortunate the results for Sarah. Thus, when Missy comes home for Thanksgiving and finds Sarah ""hauling"" at Barney's mouth, she's furious; and Sarah, seeing Missy ride off ""slim and easy on a loose rein,"" is sure she won't bring Barney back. Mom helps--mostly by talking realistically about the ways of horses. And, sure enough, Missy invites her over for some hard-nosed instruction. The upshot--after Sarah has nursed Barney through an accident (that wasn't her fault)--is sufficient success for self-respect, coupled with recognition that Barney is irrevocably Missy's. But if all goes well, Dad will buy her a horse--a fictionally necessary windup tempered, symptomatically, by pragmatic provisos. With the extras of an ingratiating goat and some deft family contrasts (Missy's, Albert's, Jill's), satisfying and sustaining.