Centers on the events leading up to the cataclysmic 1980 eruption of Mount St. Helens in Washington, with the story beginning on the day volcanic activity started on March 20, 1980, and ending on the day of the eruption, May 18, 1980.

On a train, three strangers enter each other's dreams: a woman in search of a rare herb, a man running away from his broken relationship and a desperate hobo who finds a wad of money.