When Carolyn Knapp ended her 20-year relationship with alcohol (a struggle chronicled in her bestselling book "Drinking: A Love Story"), she needed a new direction in life. What she found was a puppy named Lucille. A Pack of Two: The Intricate Bond Between People and Dogs is as touching a love story as you will ever read. In that foundling dog she plucked from an animal shelter, Knapp wrote, "I have found solace, joy, a bridge to the world."