A dog conjures feelings in memoirist Knapp (Drinking: A Love Story, 1996) that she had never allowed to surface--the giddiness and vulnerability of full-blown love--and here she endeavors to understand why. To put it mildly, life had hit a rocky patch for Knapp: Her parents had both recently died, walking papers had been served to her boyfriend, and she'd jettisoned her old pal alcohol. In walked a dog, Lucille, a shepherd mix discovered at the local pound, and the rapport was immediate. For someone so ""self-protective and locked into routines, so averse to commitment,"" Knapp thawed and connected to the dog. But why, she wonders, indisposed to let a sleeping dog lie. What forces allow people to express and experience a love that they might never hazard with another human being? For Knapp it comes down to the ""stability of fur"": Given the least chance, your dog will be there for you, accepting and ready to commune, never judgmental. Bookish by nature, Knapp has read and expresses opinions about a wide array of dog writers, from Jeffrey Moussaieff Masson to the Monks of New Skete, and she has been in contact with animal behaviorists and those who claim to communicate with dogs telepathically. And though she chides Masson for relying too heavily on anecdotes, her book is strewn with them, such as chance, telling encounters with folks out walking their dogs. For all the byways Knapp explores--dogs as agents of elucidation, vehicles for self-definition, metaphors for change, objects of indirect communication and projection--she is at her best painting the emotional landscape she inhabits with the one she loves: Lucille. Readers can't help but feel Lucille is one lucky dog living with the (yes, at times, hyper-) attentive Knapp, who has through her dog learned to invest a relationship with exuberance, humor, and an openness to mystery.