A former astronaut helps a government agent and a police detective track the source of mysterious alien pod spores, filled with lethal flesh-dissolving acid, to a South American coffee plantation controlled by alien pod clones.

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.