Joe Pickett is the new game warden in Twelve Sleep, Wyoming, a town where nearly everyone hunts and the game warden—especially one like Joe who won't take bribes or look the other way—is far from popular. When he finds a local hunting outfitter dead, splayed out on the woodpile behind his state-owned home, he takes it personally. Even after the discovery of two more bodies, and the resolution of the case by local police, Joe continues to investigate.

As Joe digs deeper into the murders, he soon discovers that the outfitter brought more than death to his backdoor: he brought Joe an endangered species, thought to be extinct, which is now living in his woodpile. But if word of this rare species gets out, it will destroy any chance of InterWest, a multi-national natural gas company, building an oil pipeline through the mountains and forests of Twelve Sleep. The closer Joe comes to the truth behind the outfitter murders, the endangered species, and InterWest, the closer he comes to losing everything he holds dear.