The border collie, Jack, and his best friend, Luke, have had a great life for the past four years with their adopted parents on their sheep ranch in Northern California. But now a pack of coyotes has started picking off the sheep and Jack feels responsible. He is confident that he and the other dogs he has trained can take care of those coyotes once and for all. But what if the predator is not a coyote, but a much larger and fiercer animal? Jack is older and slower than he used to be. Is he still up to the challenge?