Once he's on your scent, it's too late to run.

Dieter Harmon--a newcomer to the West, struggling to establish his veterinary practice--discovers the mutilated body of a hiker. The corpse has been severely mauled; the head hangs from the neck by a single strip of tattered flesh. The scene is hideous, but what terrifies Harmon are the claw marks on the victim's chest. Something has gone horribly wrong with the government's plan to restore wolves to Yellowstone.

As he seeks answers, Harmon is drawn into an escalating battle with the chief park ranger, an obsessive man who will go to any extreme to defend his dream project. For the ranger, this fight is personal. And "accidents" happen in the high country all the time.

While Harmon hunts the wilderness of Yellowstone for a killer wolf breed that shouldn't exist, he soon realizes that he's being stalked by two predators--very different in nature, but both equally deadly.