David Lightman (Matthew Broderick) is a young computer whizz who hacks into what he believes is a new line of video games, little knowing that it is in fact NORAD, America's defence program. He inadvertently creates a hostile global situation, placing the world on the brink of nuclear war. Together with his girlfriend Jennifer (Ally Sheedy) and a misanthropic computer expert (John Wood), David must fight to prevent an atomic meltdown.

Family comedy following a robot who goes AWOL. A reclusive inventor, Newton Crosby (Steve Guttenberg), is responsible for the development of a range of robots that have the capacity to destroy entire cities. At a military demonstration, one of the robots is struck by lighting and is given a life of its own. The authorities decide that this is dangerous and want the robot terminated. Number Five (voice of Tim Blaney) duly goes into hiding with a fanatical animal lover, Stephanie Speck (Ally Sheedy), who believes he is an alien. Will she be able to protect him?