Three college freshmen go missing from their rural hometown of Kelly's Falls while on Christmas break. Their cell phones, coats, and purses are left behind, but the girls have disappeared without a trace. As the days turn into weeks and the investigation grows cold, twenty-three year old Buffalo police officer Shea O'Connor is called on to dig up leads undercover. Still bearing the emotional and physical scars of a previous case, O'Connor infiltrates as eighteen-year-old Shea Anderson, a college freshman and the "niece" of the town's police chief. As she begins to immerse herself in the missing girls' world, befriending their friends and family, and doing whatever it takes to maintain her cover, O'Connor realizes the track is far colder than she initially thought. But whoever was behind the girls' disappearance was only warming up, and they have set their crosshairs directly on her. The heat is on for O'Connor as she closes in on the shocking truth about what really happened the night the girls vanished.