On the outskirts of Yellowstone National Park is Paradise Valley, Montana, home to bears, wolves, elk, and an animal so secretive, few ever get to see it: the mountain lion. Wildlife filmmaker Casey Anderson became one of those lucky few after following the tracks of the elusive cat from his backyard into the world of a mother and her three cubs. It was the beginning of what would become a remarkable relationship that gave Casey a rare glimpse into the life of a mountain lion family and a new understanding of an animal we know so little about.