When John recalls a prophetic dream and realizes that a major disaster is about to happen, he quits work, pleads with family and friends to prepare, and readies his home for the coming change. Days later, John's vision is confirmed when the Yellowstone Caldera, a massive super-volcano, erupts with devastating effect. Millions are killed instantly when cities are flattened or buried under mountains of ash. Remaining resources are quickly consumed by survivors, and those wanting to live, flee the destruction in hopes of finding food, water and shelter. More than a thousand miles away, as volcanic ash begins to fall in John's own neighborhood, chaos and terror emerge to present new challenges for the survivors. A combination of greed, anger and a base desire for self-preservation, reveals a spreading darkness beyond the ash-filled skies, where brother turns against brother, and neighbor against neighbor. The surviving government, intent on restoring order, plans to take drastic action to quell the on-going national anarchy. When John learns of the military's efforts to fulfill that plan, he quickly evacuates his company of like-minded survivors to a place of sanctuary in the Rockies, only to find that it was never his to provide.