Torn between her duties to the FBI and her need to keep her loved ones safe, former black-ops army sniper Mercy Gunderson must unleash the cold, dark, merciless killer inside her and become the predator . . . rather than the prey.
Newly minted agent Mercy Gunderson is back and ready for action-- unfortunately, she's stuck doing paperwork in an overheated government office building. But she gets more than she bargained for when she's thrown into her first FBI murder case, working with the tribal police on the Eagle River Reservation, where the victim is the teenage niece of the recently elected tribal president. When another gruesome killing occurs during the early stages of the investigation, Mercy and fellow FBI agent Shay Turnbull are at odds about whether the crimes are connected.
Due to job confidentiality, Mercy can't discuss her misgivings about the baffling cases with her boyfriend, Eagle River County sheriff Mason Dawson, and the couple's home on the ranch descends into chaos when Dawson's eleven-year-old son Lex is sent to live with them. While Mercy struggles to find a balance, hidden political agendas and old family vendettas turn ugly, masking motives and causing a rift among the tribal police, the tribal council, and the FBI. Soon, however, Mercy realizes that the deranged killer is still at large--and is playing a dangerous game with his sights set on Mercy as his next victim.

Former Black Ops army sniper Mercy Gunderson isn't adjusting well to the laid-back rhythm of civilian life on her family's ranch in South Dakota. To fill her time, Mercy accepts a temporary bartending gig at a local watering hole. Yet her attempts to settle in back home are tested when Titan Oil, a Canadian company proposing to run an underground pipeline through Eagle River County, sends Jason Hawley, Mercy's former army buddy, to the area to convince ranchers to get behind the project.
While local business owners support the pipeline, Hawley's presence riles the landowners, and Mercy is torn. After ugly threats and multiple altercations escalate tensions in the county, Mercy discovers Hawley's brutally mutilated body in the bar parking lot. When it appears Sheriff Dawson cares more about campaigning for reelection than investigating the case, Mercy vows to find Jason Hawley's killer--even if she has to run against Dawson for sheriff to ensure justice is served.
But Mercy soon learns her former military pal had plenty of secrets. Her search for the truth brings unwanted exposure to the county's dark side and risks deadly repercussions for the entire community.