Shelter killing is the leading cause of death for healthy dogs and cats in the United States. It doesn't have to be. Based on the groundbreaking book of the same name, this is the story of animal sheltering, which was born of compassion and then lost its way. It is the story of the No Kill movement, which says we can and must stop the killing. It is about heroes and villains, betrayal and redemption. And it is about a social movement as noble and just as those that have come before. But most of all, it is a story about believing in the community and trusting in the power of compassion. The film covers the history of animal shelters in the U.S. starting with the 1866 founding of the ASPCA in New York City and continuing to the present day.