When a remote camera on a large, rugged expanse held by the Land Trust for Wildlife Conservation picks up a blurry image of what could be a mountain caribou, they contact Alex Carter to investigate. After all, mountain caribou went extinct in the contiguous U.S. years ago, and if one has wandered down from Canada, it’s monumental.

But when Alex arrives on scene in the Selkirk mountains of northeastern Washington state, she quickly learns that her only challenge isn’t finding an elusive caribou on a massive piece of land. The nearby townspeople are agitated; loggers and activists clash over a swath of old growth forest marked for clearcutting. The murdered body of a forest ranger is found strung up in the town’s park, and Alex learns of a backcountry hiker who went missing in the same area the year before.

As she ventures into the forest in search of the endangered animal, she quickly finds herself in a fight for her life, caught between factions warring for the future of the forest and a murderer stalking the dense groves of ancient trees.