Louisiana Sheriff's Detective Dave Robicheaux and his longtime friend and partner Clete Purcel are vacationing in Montana's spectacular Big Sky country when a series of suspicious events leads them to believe their lives and the lives of their families are in danger. First, Alafair Robicheaux is nearly killed by an arrow while hiking alone on a trail. Then Clete's daughter, Gretchen Horowitz, runs afoul of a local cop, with dire consequences. Next, Alafair thinks she sees a familiar face following her around town but how could convicted sadist and serial killer Asa Surette be loose on the streets of Montana?