Mason Loss was a single father separated from his seven-year-old daughter, Lydia Nicole, when the United States was suddenly devastated by several massive coordinated EMP attacks. Having sustained life-threatening injuries in his search for her, he awakens from a two-year coma to find that the world is not the way he left it. To make the situation worse, Yellowstone has erupted and expelled an ancient microscopic organism that threatens the course of human survival. Now Mason must traverse the ashy suburban landscape in search of his now nine-year-old daughter. Along the way, he discovers a far more terrifying enemy than humankind can safely manage.