South Park 4: One Last Time

Two years after Stan and Wendy got married, all the other members of La Resistance have gotten married too (Kyle married Bebe, Cartman married Red, Kenny married Lola, Butters married Esther, Clyde married Annie, Craig married Heidi, Tweek married Millie, and Tolkien married Nicole), retiring from gun violence and actually making big bucks off of YouTube videos, as actors, VFX artists, and editors for Corridor. It seems as though living a normal life has worked out well. But for Stan, it isn't working out well. The truth is, he doesn't miss the violence, he doesn't miss the University (which is still under reconstruction), he misses the fun from the high school days. Kyle tells this to Wendy hours after posting a video of a guessing game regarding Disney songs, while wearing Disney outfits. An unexpected email arrives, announcing a 5-Year high school reunion at South Park High School.

Returning to South Park, CO, things are not the same as they used to be, the town has become a post-apocalyptic wasteland. No adults around, and some of the things at Stan's old house, where Stan and Wendy are staying at before the high school reunion, have been stolen. As they settle in, Stan searches the house and finds his old mementos back from the good old high school days. Shelly has her own house in Aurora, CO. Everyone meets up at the Airport Hilton Hotel trying to decide if something bad happened and it wasn't on the news, or if it is some sort of dream, all agreeing to search in the morning for answers. Meeting up in the Sunset Room for a "Welcome Back" sort of thing, drinks and music. A waiter from Airport Hilton interrupts the whole get-together to make sure they have everything. With an impatient reply from Cartman. The waiter wonders if the Cartman was that fat kid from so many years ago, which he denies, much to the relief of the waiter, who thought Cartman was a douchebag, angering Cartman.

The next day, Stan and his friends search the city to find any sign of adults around the city... none. The city is now overrun by minors, trying to survive without adults. The town is under the leadership of David Rodriguez (pronounced: Da-vee-d), as he requires Stan and the help of La Resistance to fight off the threat that has taken over the town. Stan reluctantly accepts after once vowing to never go back to the life of violence, his wedding vow to Wendy. David's base of operation is at Sodo Sopa, which is built on top of Kenny's house as his house was seen as the shitty part of South Park. Suddenly, the new kids around town are battle ready as Stan and the rest of La Resistance are being drawn back into the life of violence. The attack is from Mecha-Streisand.

Being brought back into the world of violence, David brings Stan and Wendy inside of Sodo Sopa and explains what happened. It all started one year ago when Principal Victoria got fired from South Park High after an offensive joke went viral from the school, then bringing in PC Principal, who made South Park go Politically Correct, which is what everyone avoided ever since. Mr. Garrison got offended by political correctness he decided to quit and decided to run for president of the United States. Until, an unknown call from every house saying that all the adults in town molested the children, and were taken to a Supermax prison. Stan makes Wendy gather the girls and go back to the house, as his biggest fear is losing the only woman he loves.

Before making a plan to find the Supermax prison all the adults are locked up in, the boys are attacked by Ads disguised as Angry Yelpers, led by Leslie, who were responsible for shutting down Whistlin' Willy's, the best place in all of South Park. During the fight, a flare is sent up, as the boys are getting overrun with Ads, and Stan gets shot in the arm. Wendy and the girls show up and save the boys. Back at Stan's house, he tells the Wendy that he and the guys will catch up with them as David treats his arm, knowing this isn't the high school reunion they were expecting, Stan makes a call to the girls about one last time, this time it's personal.

All of the adults are released and back home, thanks to Sharon Marsh, who survived the blast from two years ago. The Fighters of Zaron reunite, and with more allies: Mr. Garrison, Principal Victoria, Mr. Mackey, PC Principal, Strong Woman, the PC Babies, Chef, the parents, and every other character canon in the TV series. Wendy reveals to Stan that she is pregnant with twins, making it her "One Last Time." The entire city has an Avengers: Endgame "Portals" moment with each bus arriving with all the supporting characters. A war breaks out in all of South Park, fighting against an enemy that was summoned by the elderly: ManBearPig. Al Gore reveals that ManBearPig exists and was responsible for everything over the past 5 years: Saddam Hussein, Scott Tenorman, Trent Boyett, Woodland Critters, Jared Fogle, the Giant Guinea Pigs, Crab People, and the Ads. And raises an army of all the past enemies. This fight angers Satan, who rises from the underworld and takes on ManBearPig himself. But ManBearPig has the upper hand, and kills Satan with one of his horns. Al Gore reveals to Stan why ManBearPig is here, the elderly were wreckless and greedy in their youth, and made a deal with ManBearPig to keep their "cool shit" to themselves. And now, ManBearPig has come back, to punish him and his friends for the elderly's mistakes (Every dystopian sci-fi/fantasy YA novel ever: adults make a mistake that causes the world to go to shit and they put the blame on the younger generations and force them to fix it).

In an intense duel between Stan and ManBearPig, Stan's Grandpa, Marvin, arrives and gives him a syringe full of concentrated Gluten. As Stan gets disarmed, he then gets the upper hand by injecting the Gluten into ManBearPig, and the dick flies off, killing ManBearPig. This results in all the enemies of the past to disintegrate and sent back to Hell, which now has no ruler because Satan is accepted into Heaven. Soon it is discovered that all their past enemies were just disguises, the real villains all along were Crab People. Knowing that the war nearly cost the lives of everyone in town, including La Resistance, the only other death besides Satan is Kenny. A Tony Stark-style funeral is held for Satan, Kenny is shown to be alive after being reborn again.

It is time for the high school reunion, and remembering how great high school was compared to how shitty college was. The reunion is held at South Park High, and it becomes a "I forgot what this felt like" moment for everyone. One week after the reunion, the thought of other threats out there still rings in the ears of the citizens. Stan has everyone in town work together to build city defenses from threats, inside and out. The defenses will forever protect the city of South Park, and our young heroes no longer have to fight. La Resistance leaves South Park for good, only to return for high school reunions, family occasions, and... whatever.

17 Years Later
At a beach house in Malibu, CA, Luke and Arianna Marsh (Stan and Wendy's twins), play JUST DANCE (playing "Blinding Lights" by The Weeknd), waiting on mom and dad to show up, asking their cat Sully, "Where are they?" As they search around the house, finding a bunch of things from their parents' past, looking for them. Luke finds a letter from Kyle and Bebe, saying that they and their daughter Alice, will be visiting for a sleepover video. Arianna finds a stash of photos: Stan and Wendy's wedding, them and their friends at the End-of-year Gala, with guns, prom photos, family photos, and Arianna's quinceanera. Wendy is with the girls at Kyle and Bebe's house getting ready for a Halloween JUST DANCE Competition. It appears everyone at La Resistance has become very successful YouTube stars and producers, becoming a new sub-division of Corridor. Stan (Age 40) and Wendy (Age 39) arrive home, seeing that their kids have discovered a stash of photos from their past. Stan thinks it's time for his kids to know what happened, but Wendy isn't 100% sure, and shows them his gunshot wound from 17 years ago, it's still there. They're older than him when he, Kyle, Cartman, and Kenny started getting involved in crazy shit. And so, he tells them his side of the story as he gets his kids prepared for the Halloween JUST DANCE Competition.

In a post-credit scene, the Halloween JUST DANCE Competition concludes with Stan jackin' it in San Diego.