When Redwoods Park Enforcement Ranger Kathleen Shepherd finds a third dead bear in the forest, its paws and gallbladder harvested, she contacts U.S. Fish and Wildlife Services for assistance. They send Nick Tanner, one of an elite cadre of undercover USFWS Special Agents.

Highly valued in Traditional Chinese Medicine, bear gallbladders fetch the type of money that attracts dangerous and desperate criminals. When the killing of bears escalates to a series of equally macabre human murders, Nick and Kathleen follow the clues that lead them into a lethal trap-all under the darkly surreal canopy of the world's oldest known living organisms, the old-growth redwoods.