A deeply touching portrait of a remarkable animal, Merle's Door explores the issues that all animals and their human companions face as their lives intertwine. Author Ted Kerasote presents the latest research into animal behavior as well as the origins and evolution of human-dog interaction. Kerasote's adopted Labrador mix, Merle, showed the author how dogs might live were they free; the author suggests how they should be allowed to live and the doors that should always remain open to them.