Sam Rivers, wildlife biologist and special agent for the U.S. Fish & Wildlife Service, has a penchant for understanding predators. His expertise finds him returning to Defiance, Minnesota, his boyhood home on the Mesabi Iron Range, a home he hasn't seen in twenty years. There, he investigates wolf depredation of local livestock--but the mysterious death of his estranged father lands the agent on a case unlike any he's worked before. His knowledge of cold, wilderness and wolves was bred in his bones. He learned his lessons well, and now he'll need to use them.