FBI Special Agent Meg Jennings and her Labrador, Hawk, are participating in a water search training weekend in the Boundary Waters area of Minnesota. The competition has attracted participants from all levels of law enforcement, each vying to win. The races are challenging, the rivalry is intense, and Meg is already under pressure when Hawk alerts to a scent in the water - and discovers the fresh body of one of Meg's fellow competitors. The victim had made an unfounded complaint about her, one that could cost Meg her job and see Hawk removed from her care. Meg's team flies out to Minnesota to help uncover the truth, but they're on unfamiliar territory, pitted against a killer with the skills - and the motivation - to stay hidden in plain sight.