Some info and a short description of this South Park episode on South Park Zone:
South Park - Pre-School is the 121st episode and the 10th in season 8 of the Comedy Central series South Park. It originally aired on November 10, 2004.
In this South Park episode, Stan tells the boys that Trent Boyett, a classmate from their preschool years, has been released from juvenile hall, a fact that makes the boys panic and come up with a plan to defend themselves from Trent's revenge. This sends our boys from South Park into hiding.
South Park Spoiler Alert!
(The complete plot for this South Park Episode)
This South Park episode begins with Stan acting in panic and terrified announces to Kyle, Kenny, Cartman and Butters that Trent Boyett, a notorious bully from their preschool years, is being released from juvenile hall after a five year sentence. This causes the boys to worry and devise a plan to defend themselves from Trent's anger.In a flashback set five years previously, the boys got the idea to play "Fireman", which involved starting a real fire and extinguishing it.
Wanting to put out an actual fire, they ask Trent to start one. However, the fire soon gets out of control and their teacher, Miss Claridge, is badly burned while trying to put it out. Shortly afterwords, the police arrive and instead of taking what might have been the easier route by saying it was an accident and risking getting into trouble, the boys use Trent as their scapegoat - the boys lie and say they weren't involved. When asked by Trent, Butters refuses to speak in Trent's defense, as he feared he would be grounded for getting involved. Trent is sentenced to five years in juvenile hall, and the boys forget it ever happened until now, five years later.
Miss Claridge is burned so badly that she is forever confined to a sort of iron lung/motorized wheelchair, and she can only communicate by using an electronic beep: once for "yes", twice for "no."
Butters is the first of the boys that Trent confronts when his parents forced him to go outside to play and not listen to his screams, which results in a hospital stay for Butters, who sustains, according to the Doctor, a number of childhood pranks, including a massive snuggie, two Indian sunburns, a charlie horse, a second degree titty-twister, a "colossal" swirlie, a noogie and something called a "Polish bike ride" (Which has no cure). He appears to be in a trauma-induced coma.
To avoid Trent doing to them what he did to Butters, the boys go to the sixth graders for help. When they arrive at the hangout, the sixth graders say that they'll only defend them if they get a picture of Stan's mother's "twins".
The boys improvise by taking a photo of Cartman's buttocks, which they dress up to look like "twins".
After the boys give the photo to the sixth graders, they agree to protect the boys, and they then decide to take the photograph behind a set of bushes. The boys are initially relieved, only to later discover that Trent dispatched all of the sixth graders single-handedly, sending them to the hospital with injuries similar to Butters'. With no one left to turn to, the boys ask Stan's sister, Shelley, to defend them, but she only agrees to help them on the condition that they confess to Miss Claridge what really happened five years ago.
The boys meet Miss Claridge, who is still stuck in the middle of the street and attempt to make peace with her. At this moment, however, Trent arrives to finish business. The boys try to talk with him, but Trent still does not want to settle, he mentions about the things he's missed out on such as a talking Christmas Poo and fighting a huge mechanized Barbra Streisand and adds that once his retribution is over, the matter will be solved for good. Once again instead of taking the easier route, Cartman takes out his mother's taser and fires it at Trent, however he misses, instead shocking Miss Claridge, recharging her wheelchair to such a degree that it goes out of control. The wheelchair spins in place then crashes into a propane shop, causing an explosion which destroys the shop and sets Miss Claridge on fire. Ablaze once again, Miss Claridge crashes into an hydrant, where the flames are put out.
The police then arrive and ask Miss Claridge if Trent tried to kill her again. She replies "no" with two beeps, but the police misunderstand this to mean "yes, yes" and arrest Trent. The boys, having learned nothing from the experience, make the same mistake that they made five years before, claiming that they were not involved with the incident at all. When Kyle points out that Trent will be angered when he gets out of juvenile hall, Cartman dismisses this, saying, "Whatever, that's like five years from now!" As Cartman moons Trent, who becomes quite angered by this, the sixth graders happen upon the scene, and see Cartman's buttocks, recognizing them as the "twins" from the photograph, they pick Cartman up and carry him to the bushes.