Two campers in the New Jersey woods have their outdoor fun interrupted by the arrival of a meteorite crashing nearby. They go to investigate the crater, but are suddenly attacked and devoured by alien parasites who have hitched a ride to Earth. After finishing off the campers, the hungry space monsters head for a nearby town, where they make their domain in the basement of an old house soon begin polishing off one hapless inhabitant after another. Four young teenagers, plus one pre-teen boy, try to find a way to stop the angry space monsters before they reproduce and literally eat humanity.
Meet Joel Goodson, an industrious, college-bound 17-year-old and a responsible, trustworthy son. However, when his parents go away and leave him home alone in the wealthy Chicago suburbs with the Porsche at his disposal he quickly decides he has been good for too long and it is time to enjoy himself.
God throws his hands up at the foolishness of humanity and orders the race destroyed. A trio of bleeding-heart angels strike a deal with him: if they can find just two good souls, the Lord will allow Earth to survive.
High School student David Lightman (Matthew Broderick) has a talent for hacking. But while trying to hack into a computer system to play unreleased video games, he unwittingly taps into the Defense Department's war computer and initiates a confrontation of global proportions! Together with his girlfriend (Ally Sheedy) and a wizardly computer genius (John Wood), David must race against time to outwit his opponent.
Aiming to defeat the Man of Steel, wealthy executive Ross Webster hires bumbling but brilliant Gus Gorman to develop synthetic kryptonite, which yields some unexpected psychological effects in the third installment of the 1980s Superman franchise.