A comet is hurtling toward Earth and could mean the end of all human life. The U.S. government keeps the crisis under wraps, but crack reporter Jenny Lerner (Tea Leoni) uncovers the truth -- forcing U.S. President Beck (Morgan Freeman) to announce his plan. Grizzled astronaut Spurgeon "Fish" Tanner (Robert Duvall) and his team will land on the comet and lay explosives, hopefully deterring the object from its doomsday course. If not, humanity will have to prepare for the worst.