A teenage astronomer and his teacher discover an object amongst the stars at night. Little do they know that it's a comet on a direct collision course for earth. After the teacher dies in a car crash trying to report his findings the President(Morgan Freeman) announces the comet's existence. He also states that there is no need to panic, because NASA is going to send astronauts on the space mission, Messiah. Their mission is to destroy the comet before it gets too close to the earth. When Messiah backfires, the President announces that special caves will have to be built, and the government will have to have a lottery-of-fate to randomly select 800,000 ordinary American citizens to go along with 200,000 scientists, soldiers, and other officials. These 1,000,000 people will be set aside to save the population from extinction when the comet hits.