Reclusive polar ice researcher Seth Peterson has located a doomsday fault, which could allow the West Antarctic Ice Sheet -- a hunk of ice a mile-and-a-half-thick and as big as Mexico -- to slide off the continent and flood coastal cities, ending the world as we know it. Millions of people worldwide would perish in the resulting chaos and famine. This knowledge -- and his heroics at a fateful traffic accident -- puts Seth reluctantly under the scrutiny of media, law enforcement, and a band of environmental extremists desperate to make an obscure, overdue prophecy come true. Their cataclysmic objective seems terrifyingly believable to Seth -- as does their plan to exterminate him, the only living witness to their scheme. In fear for his life, Seth escapes to the icy shores of a Minnesota lake, where he must confront these extremists in order to prevent a potential disaster.