But back to usual business at Third Street School, TJ and his pals sneak ice cream right out from under Ms. Finster's nose and share it with all of the children of the playground. When Ms. Finster finds out, T.J. disguises his voice as Principal Prickly and tells the students that they should scarf down every last bit of ice cream found on the playground, and tells them Prickly has a "fat, saggy butt", making the students roar with laughter, at which point Principal Prickly catches him in the act.
Dr. Phillium Benedict, (voiced by James Woods) the former Secretary of Education (fired after trying to abolish recess nationwide in a prior episode) and former principal of Third Street School, steals a tractor beam and places it in the school during summer vacation. He plans to use the device to alter the moon's orbit, thereby altering the weather and creating permanent winter, and even get rid of summer vacation. He hopes to raise test scores by doing this (and become president).
T.J. Detweiler is the only kid in town (aside from Randall) who doesn't go to a summer camp. Bored and friendless he rides by Third Street Elementary School one day only to notice strange events are taking place-- an eerie green light is emanating from inside the school. T.J. tries to tell his parents and the cops, but no one believes him (the cops laugh out loud when anyone tries to suggest what is really going on, a running gag throughout the movie). He finds Principal Prickly at the West Side Golf Course and brings him to the school (the principal is still skeptical and annoyed from being pulled from his game in the middle of his vacation) where he is promptly "dematerialized" (really kidnapped through some kind of teleporter) on the front step, leaving only his golf shoes. Later, with some help from his sister, TJ gets his friends together. They do not believe him either...until they see Benedict's tractor beam come out of the school and fire a green ray into the sky.
They all try to stop Benedict, but fail on their own. In order to save the world as they know it, every single student in school is brought in, including the former sixth graders, such as King Bob. Additionally, Ms. Finster arrives with the rest of the school's faculty to stop Benedict - they, like the pupils, refuse to give up the largest period of time when they don't have to worry about school. In the midst of a large battle between Benedict and his men vs. the students and teachers staged in the laboratory (really the upgraded auditorium), Vince destroys the photon channeler using a baseball and the kids and teachers win. Despite his persistence, Benedict and his henchmen are defeated and arrested, and the series essentially ends. With Benedict and his men in jail, Mikey, Gus, Gretchen, Spinelli and Vince decide to spend their summer with T.J., because they have plenty of time to prepare for their futures, but they only have a little time left for just being kids. One thing T.J. should remember though-- by the time the new school year starts, he still has a meeting with Principal Prickly-- he hasn't forgotten the "saggy butt" comment. It should be noted that themes such as good vs. evil, growing up, and to some extent the loss of innocence are prevalent in this film.
Note: "Purple Haze" by Jimi Hendrix was also used in the film, though it is not included on the soundtrack.
Despite the mixed reviews, the film was a Box Office Success at the US and Canada Box Offices, earning $36,706,141 at the Domestic Box Office rate. However it performed poorly at Overseas Box Offices, earning only $7,754,709, with a total worldwide rate of $44,460,850.