The film is inspired by the idea of a global doomsday event coinciding with the end of the Mayan Long Count Calendar's current cycle on or around December 21, 2012 (the northern hemisphere's winter solstice).
Jackson Curtis (John Cusack) is a divorced father who occasionally works as a limousine driver and a writer, while his ex-wife Kate Curtis (Amanda Peet) and children live together with her new boyfriend. In Guatemala reports start coming in of mass suicides in the Mayan jungles of people attempting to avoid the impending apocalypse.
The IHC (Institute for Human Continuity), a secret organization, has realized the situation and begins constructing vast arks beneath the Himalayan mountains designed to withstand most natural disasters in order to save both humanity, significant species, and the greatest treasures of mankind for when doomsday finally happens.
There are arguments however about how and when the governments of the world will alert their fellow citizens and even discussions about how the remaining survivors will be selected to survive Armageddon, but when they discover that the global cataclysm is happening much faster than expected, they must race to these ships to save the human race before all is lost.