A horrified Stan 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.
In a flashback set five years previously, the boys express interest in playing "fireman", a game in which they extinguish a fire by urinating on it.
She softens her usually-mean stance against them upon seeing how truly terrified of Trent her brother is and offers protection, but only if they confess to Miss Claridge that they were the ones who burned her five years ago.
The boys meet Miss Claridge, who now must use a futuristic machine to get around and beep a single light on it once to say "yes" and twice to say "no", and attempt to confess about what happened five years ago, but Trent arrives to confront them before they can finish.
[1] "Preschool", along with the thirteen other episodes from South Park's eighth season, was released on a three-disc DVD set in the United States on August 29, 2006.