Many visitors to Yellowstone National Park don't realize that the boiling hot springs and spraying geysers are caused by an underlying supervolcano. It has erupted three times in the last 2.1 million years, and it will erupt again, changing the Earth forever. Fifteen-year-old Alex is home alone when the supervolcano erupts. His town collapses into a nightmare of darkness, ash, and violence, forcing him to flee. He begins a harrowing trek in search...

Nearly a year after the eruption of the Yellowstone supervolcano, survival has become harder than ever and Alex and Darla must risk everything to try to create a community that can withstand the ongoing disaster.