C.J. Box delivers a classic thriller churning with tension and a need for revenge. A case gets personal for Wyoming game warden Joe Pickett when he learns that his eighteen-year-old adopted daughter, April, has been found bludgeoned at the side of the road outside Saddlestring and left for dead. Joe is out checking on the slaughter of a lek of sage grouse when he gets the call, the birds close to inclusion of the federal government’s list of endangered species. If the sage grouse make the list, the economy of several Western states will be radically affected, putting an end to energy development on hundreds of thousands of acres. It is a classic state versus federal controversy. While a pair of agents--Annie Hatch of the Bureau of Land Management and Revis Wentworth of the U.S. Fish and Wildlife Service, members of the recently established Emergency Sage Grouse Task Force--take over that investigation, Joe turns his attention to his daughter.

Pickett meets with Sheriff Mike Reed at Twelve Sleep County Hospital in Saddlestring, where April will be airlifted to Billings, Montana, for specialized care. She remains unconscious, the extent of her injuries as yet unknown. Joe’s wife, Marybeth, rides to Billings with her daughter, Joe staying home to care for sixteen-year-old Lucy and contact older daughter, Sheridan, at the University of Wyoming, only when there is a diagnosis. For the time being, Joe reigns in his temper and his certainty that April’s rodeo star boyfriend, Dallas Cates, is somehow responsible for April’s condition. No one has seen April since she ran off with Dallas to do the rodeo circuit, but Joe wants answers, held in check only by Sheriff Reed’s warning to let the police do their job. He is allowed to accompany the sheriff on the interview, but only if he shows restraint.

Joe’s only intent at this point is to demand an accounting from Dallas, disappointed--but still suspicious--when told that Dallas is incapacitated by injuries from a recent rodeo accident and physically incapable of hurting April. It is Pickett’s first visit to the family compound, Dull Knife Outfitters, although he is aware that Eldon Cates has a secret hunting camp for high rollers no one has ever located. Along with an off-season sewage collection business run by Eldon and his son Bull, Joe is familiar with Bull’s rowdy wife, Cora Lee, but has never encountered the family matriarch, Brenda. Dallas is Brenda’s pride and joy: she goes to great pains to convince the sheriff of her son’s innocence in April’s beating. The third Cates son, Timber, is incarcerated, though soon to be released. As April remains in an induced coma, Joe learns the depth of depravity that is the Cates family, a lawless, secretive bunch with violent hearts and plans of their own afoot. These people are the stuff of nightmares, more devious and dangerous than even Joe can imagine.

Between the sage grouse investigation and identifying April’s attacker, Box adds another thread to the plot--Joe’s renegade falconer friend, Nate Romanowski, currently incarcerated by the feds. In a plea deal that will exchange his freedom for an opportunity to lure bigger prey (Nate’s former boss, millionaire Wolfgang Templeton), Nate agrees to truly draconian terms, released with trackers attached both to his ankle and his wrist, monitored by an agent determined to see him fail. Heading off to a Wyoming ranch to begin his first business assignment as a falconer with partner Liv Bannon, Nate is drawn tangentially into the unfolding drama of April’s attack with shocking results and a unique twist that is classic C.J. Box. Endangered unrolls in a series of violent confrontations and bizarre life-and-death collisions with a group of people as evil as any Badlands killers. Once set in motion, events move at a punishing pace, every member of Joe’s family involved in a thriller that is impossible to put down.