At the age of 36, Caroline Knapp, author of the acclaimed bestseller Drinking: A Love Story, found herself confronted with a monumental task: redefining her world. Eighteen months to the day after she quit drinking, Knapp stumbled upon an eight-week-old puppy at a local animal shelter, took her home, and named her Lucille. Now two years old, Lucille has become a central force in Knapp's life. In Pack of Two, she brings the same perception and talent to bear on the rich, complicated terrain of human-animal relationships. In addition to mining her own experience with Lucille, Knapp speaks to a wide variety of dog people - from animal behaviorists and psychologists to other owners whose dogs have deeply affected their lives - about this emotionally complex, sometimes daunting, often profoundly healing alliance. Throughout, she explores the shift in canine roles from working partners to intimate companions and looks, too, at how this new kinship, this wordless bond, becomes a template for what we most desire ourselves.