Estes Park Police Chief Marcus Colton and tracker Sam ‘Raven’ Spears have never liked one another, but when a young girl goes missing in Rocky Mountain National Park, Colton hires Spears to help find her. Their search ends after a night of devastating horror. When word reaches Estes that the nation has been hit by a coordinated electromagnetic pulse attack, Colton and Spears are forced to work together again. But they quickly realize they aren’t just tracking a killer–they are tracking a madman. As the United States descends into chaos, the hunters become the hunted.