Katie Cathcart's gruesome murder in the remote Crazy Mountains of Montana points at an eccentric modern day mountain man, Bridger Jackson, living in a hidden cave away from society. Ignoring the sheriff's warnings and bent on revenge for his sister-in-law's death, JJ Volker grabs his gun and goes tracking Jackson's trail in hopes of not only avenging Kaitie's death but of reestablishing the love of his wife. His expert tracking techniques make him the only man likely to be able to locate the mountain man from whom he learned those techniques, Bridger Jackson. But is he on the right trail to find either?