An explosion rocks Yellowstone. A strange disease begins to spread. A supervolcano threatens to erupt. And none of it was an accident. A reclusive Yellowstone park ranger is forced into action, teaming up with a beautiful woman from the CDC. Harvey Bennett isn't a trained killer, but he'll fight for what's right. And he'll do anything to take down the terrorists behind the attack. From Yellowstone across the American landscape, Harvey and Juliette must do what it takes to survive, before it's too late.