C.J. Box 
Wolf Pack [EPUB ebook] 

THE HUNT IS ON. The good news is that Joe Pickett has his job back. The bad news is that Wyoming’s Twelve Sleep County game warden is only days away from the most dangerous predators he’s ever faced. Joe’s working with Katelyn Hamm, his counterpart in adjacent Shell County, to trace a drone operator whose aerial acrobatics have been stampeding elk and deer to their deaths. Their investigation will put them both on a collision course not only with the FBI, but also with the Wolf Pack, a remorseless quartet of killers. Coming up from the south, the Wolf Pack have been tracking their prey across the USA. Behind them, a trail of dead – ahead, their target. They will let nothing will get in their way – especially two game wardens. 'Terrific plots, muscular writing, unlikely heroes and wild terrain’ DAILY MAIL. 'An exemplary writer of crime novels’ FINANCIAL TIMES.