FBI special agent Mercy Kilpatrick has been waiting her whole life for disaster to strike. A prepper since childhood, Mercy grew up living off the land — and off the grid — in rural Eagle’s Nest, Oregon. Until a shocking tragedy tore her family apart and forced her to leave home. Now a predator known as the cave man is targeting the survivalists in her hometown, murdering them in their homes, stealing huge numbers of weapons, and creating federal suspicion of a possible domestic terrorism event.

Twenty years ago Emily Mills's father was murdered, and she found his body hanging in the backyard. Her younger sister, Madison, claims she was asleep in her room. Her older sister, Tara, claims she was out with friends. The tragedy drove their mother to suicide and Tara to leave town forever. The killer was caught. The case closed. Ever since, Emily and Madison have tried to forget what happened that night - until an eerily similar murder brings it all back.

When an eleven-year-old is abducted on her way to school, the FBI doesn’t waste a moment, sending agents to scour the area and embedding Special Agent Ava McLane with the distraught family. In the eye of the storm is local detective Mason Callahan, whose life is crumbling to pieces - he’s related to the victim, and his longtime confidential informant has just been murdered.

While fighting in Afghanistan, Major Grant Barrett receives devastating news: his brother and sister-in-law have been murdered in Scarlet Falls, the sleepy suburb of Grant's youth. Emotionally scarred from war, the career soldier returns home on emergency leave to temporarily care for his orphaned nephew and niece. But when someone tries to kidnap the kids and their teenage babysitter, Grant knows it's not a random act... and neither were the murders.

When a man is shot in the head, Bree Taggert and her new partner, veteran detective Dana Romano, respond to the call. They break the news to the victim’s ex-wife and learn the estranged couple’s five-year-old daughter was supposed to have been with him. What starts as a murder investigation quickly morphs into a desperate search for a missing child. The case stirs memories of Bree’s own traumatizing childhood. To find the little girl, Bree will have to relive her own terrifying past.