Wyoming game warden Joe Pickett faces his most dangerous adversary yet in award-winning author C. J. Box's thrilling new novel.

It's an idyllic late summer day in Saddlestring, Wyoming, and game warden Joe Pickett is fly-fishing with his two daughters when he stumbles upon the mutilated body of a moose. Whatever-or whoever-attacked the animal was ruthless: Half the animal's face has been sliced away, the skin peeled back from the flesh. Shaken by the assault, Pickett begins to investigate what he hopes is an isolated incident.

Days later, after the discovery of a small herd of mutilated cattle, Pickett realizes this is something much bigger. Local authorities are quick to label the attacks the work of a grizzly bear, but Joe knows otherwise. The cuts on the moose and the cattle were too clean, too precise to have been made by jagged teeth. Are the animals only practice for a killer about to move on to a different, more challenging prey?

Joe's worst fears are realized when the bodies of two men are discovered within days of each other, their wounds eerily similar to those found on the moose and cattle. There's a vicious killer, a modern-day Jack the Ripper, on the loose in Saddle-string-and it appears his rampage is just beginning.