A group of men discuss the development of a laser beam weapon capable of shooting targets from outer space, deemed the “crossbow project.” Central Intelligence Agency (CIA) agent, Dave Decker, demands the top secret weapon be ready for use within four months, and Major Don Carnagle promises to put pressure on the developing scientist, Dr. Jerry Hathaway, to perfect the laser. An agent named George is concerned that the President of the United States is unaware of the unethical project, and asks to be reassigned. Decker remarks that he will need to be “liberated” from the project. Elsewhere, Dr. Hathaway arrives at a high school science fair to deliver the news to fifteen-year-old Mitch Taylor that he has been accepted at Pacific Tech college. The awkward boy is teamed with senior, Chris Knight, a fellow genius, who will be Mitch’s mentor. Fun-loving Chris skips his classes, and orchestrates an indoor ice-skating rink in the halls of their dormitory. Mitch and Chris work on Dr. Hathaway’s laser beam project, and Mitch is given a leadership role, much to the chagrin of classmate, Kent. Mitch is curious about a mysterious former student, Lazlo Hollyfeld, who disappears into Mitch’s closet several times a day. Upon exploration, he finds a trap door inside the closet, which leads to Lazlo’s secret underground laboratory. Sometime later, Chris is ordered by Dr. Hathaway to produce results faster, but Chris ignores him, and takes Mitch to a swimming party instead of working. At the party, Mitch begins to have feelings for awkward co-ed classmate, Jordan. Kent spies on the boys, and reports their truancy to Dr. Hathaway, who arrives and scolds Mitch. Embarrassed, Mitch telephones his parents, begging to come home, and Kent records the conversation, later replaying it over loudspeakers in the crowded cafeteria. Chris encourages Mitch to have fun at school, and seek revenge on Kent. With the help of Chris and Jordan, Mitch takes apart Kent’s automobile, and rebuilds it inside of Kent’s dorm room. Sometime later, Chris visits Dr. Hathaway at his home, and sees Agent Decker and Major Don Carnagle leaving. Chris inquires about the men, but Dr. Hathaway ignores him. Under pressure from Decker to perfect the laser, Dr. Hathaway dismisses Chris from the project, and warns that he will not receive a diploma. Mitch encourages Chris to get even, and they continue their own laser experiments. In time, Mitch admits his feelings to Jordan, and kisses her. Kent sabotages Chris’s work; however, the mishap leads Chris to a discovery about Dr. Hathaway’s laser project. Chris successfully demonstrates his theory, and Dr. Hathaway promises to grant him a diploma. When the peculiar former student, Lazlo Hollyfeld, approaches Chris with his thoughts that Dr. Hathaway’s laser is meant to be used as a weapon, Chris and his friends race to retrieve the machine from the laboratory, but find it missing. They trick Kent into revealing the whereabouts of the laser, and follow Dr. Hathaway to a classified meeting at Marsh Air Force base, using disguises to get on site. The friends work together to recalibrate the coordinates of the machine. The following morning, the Air Force sends the laser into outer space to conduct a test on its beam strength, and creates a target in the desert. However, Chris, Mitch, and friends wait outside Dr. Hathaway’s home, which they have recalibrated as the target. Inside, they have filled his living room with un-popped popcorn kernels. Kent arrives and enters the house, ignoring his rivals’ warnings. When the laser beam is activated, it hits the house, and pops the kernels, blowing out the doors and windows, and lifting the roof. After it launches, the laser self-destructs, due to Chris and Mitch’s sabotage. At the control center, Dr. Hathaway tracks where the laser beam landed, and discovers that his home was the target. He returns to find his house destroyed, and his yard covered in popcorn.