On a snowy December night, single mother Rebecca Carter drives her van into a snowbank to avoid hitting an elk on a desolate mountain highway. She is at the end of her rope, out of money and food. Still, she refuses help from a man in a pickup truck--Rebecca's adolescent daughter, Moonflower, is on the run from a grisly secret, and the last thing they can afford is to be remembered by anyone they meet. Meanwhile, Special Agent Marc Donner of the FBI has spent the better part of two years hunting down a gruesome serial killer who drains victims of blood before severing their spinal cords, leaving a trail of bodies throughout the country. As Agent Donner's investigation brings him closer and closer to where Rebecca and Moonflower are hiding out, in the foothills of Colorado, the life that Rebecca has fought so hard to hold together for her daughter becomes increasingly imperiled. In this deadly, high-stakes game of cat and mouse, nobody is safe and nothing is certain--not even the line between predator and prey.