In May 1997, at a star party, teenage amateur astronomer Leo Beiderman discovers an unusual object. He sends a picture to astronomer Dr. Marcus Wolf, who realizes it is a comet on collision course with Earth. Wolf dies in a car crash while racing to raise the alarm.
A year later, journalist Jenny Lerner investigates Secretary of the Treasury Alan Rittenhouse over his connection with "Ellie", whom she supposes to be a mistress. She is abducted by the FBI to meet President Tom Beck, who persuades her to sit on the story for 48 hours in return for a prominent role in the press conference he will arrange. She subsequently discovers that "Ellie" is actually the acronym "E.L.E.", for "extinction-level event". Two days later, Beck announces that the comet Wolf-Beiderman is headed for Earth and could cause humanity's extinction. He reveals that the United States and Russia have been constructing the "Messiah" in orbit, a spacecraft to transport a team to alter the comet's path with nuclear bombs.
