Continuing the events of South Park: Post Covid, Stan Marsh has flashback memories of when he, Kyle Broflovski, Kenny McCormick and Eric Cartman were all sent home from school due to COVID-19 before they could implement their plan to blackmail classmate Heather Williams into getting them courtside Denver Nuggets seats, and the resulting malaise which eventually led to him burning down the Tegridy Farms marijuana farm and inadvertently killing Shelly Marsh, which led to Sharon Marsh committing suicide. All of South Park is still under quarantine due to the new COVID variant. Randy Marsh has escaped from the Shady Acres retirement home with his last sprout of marijuana from Tegridy Farms, but just as he is about to be captured by retirement home workers, Token Black beats up the workers and takes Randy to Kenny's lab. At the lab, Stan, Kyle, Wendy Testaburger, Tweek Tweak, Craig Tucker, Jimmy Valmer and Clyde Donovan cannot get past Kenny's firewall without a voice command from Kenny or Kenny's assistant, "Victor Chouse", who is confined to a mental institution. Wendy also realizes that they will need aluminum foil for the experiment, but all aluminum foil is currently stuck in cargo ships at Long Beach. Stan and Kyle set out to the mental asylum to retrieve Victor Chaos while Tweek and Craig try and find aluminum foil.Kyle and Stan arrive at the South Park Mental Asylum, and when Kyle reads Victor's file, he sees the patient's name is Victor Chaos. Kyle and Stan enter Victor's room to discover that Victor Chaos is actually Butters Stotch, who is now fully engulfed in his Victor Chaos persona after having been accidentally grounded in his room by his parents for 16 years. Chaos is obsessed with making money via NFTs, but as soon as he mentions the subject, mental doctors subdue Chaos and remove Kyle and Stan from his cell. The main doctor explains that Chaos was so adept at convincing others to invest in NFTs that he had to be locked away; in the meantime, Chaos uses a piece of paper given to him by Kyle and Stan to convince a guard to let him out and he escapes from the asylum.Back in the lab, Randy uses aquaponics to cultivate his marijuana plant into more sprouts when the others explain to Randy their plan to send Kyle and Stan back in time to the moment Randy had sex with a pangolin in China and thus stop COVID from happening, while Randy is convinced that restoring his marijuana is the solution to their problem. When Wendy asks the government for more power for Kenny's lab, they initially agree to help, but when they discover that Clyde is not vaccinated, they refuse. Clyde defends himself by saying an expert once told him not to get vaccinated.At the South Park Church, Scott Malkinson is praying when Eric Cartman, his wife Yentl, and their children Moisha, Hackelm and Menorah arrive asking for help. Cartman promises to do whatever it takes to stop Kyle and his plans. He uses the church to form a "Foundation Against Time Travel" while hiding his wife and children in the attic of the church. Tweek and Craig arrive at the church and inadvertently tell Cartman their need for aluminum foil; he captures them and suspends them from the ceiling. Cartman convinces Clyde to join his group and Clyde reveals that Butters (Chaos) is the key to the process. Cartman finds Butters attempting to sell NFTs to senior citizens and strongarms him into joining his side. Cartman brings Butters to the lab to get his Victor Chaos persona to convince everyone to invest in NFTs. When Kyle and Stan arrive at the lab, Wendy, Token, Jimmy, and Randy have been brainwashed by Chaos and are obsessed with NFTs. Cartman, Clyde, and Butters have stolen all the equipment and are setting up at the church with Scott and Kevin. Cartman reveals his plan is to send Clyde back in time and kill younger Kyle to stop Kyle's time travel plans, while Kyle and Stan bring everyone else at the lab back to their senses. Wendy states that Kenny's plan was not to go back to the beginning of COVID, but to March 10, 2021 (the date of the "South ParQ Vaccination Special") and stop the boys from breaking up. Token states that the only reason Tegridy Weed was included in Kenny's notes was because he wanted some marijuana for the trip. Randy, depressed that there was nothing special about his marijuana, forgives Stan for his actions and gives Stan his last seed of marijuana that was not taken.Cartman readies Clyde to go back in time, but as the machine powers up, Stan and Kyle arrive and use their Amazon Alexas to neutralize Butters. Cartman defends himself to Kyle and the two have a fight. Yentl convinces Cartman to stop, and Cartman agrees to let Kyle go through with his plan, but Cartman's infant son throws the switch and sends Clyde back to March 10, 2021. Clyde arrives and goes to his old house to get his dad's gun where he convinces his past self not to get vaccinated by claiming to be an expert. On the bridge where the boys are about to break up their friendship, Clyde arrives to shoot young Kyle, but Stan and Kyle arrive, having traveled through time to stop Clyde. Clyde attempts to shoot young Kyle, but Cartman, having time-traveled as well, shoots Clyde to death first. Stan, Kyle, and Cartman decide to fix their friendship by completing their plan to blackmail Heather Williams to get their younger selves courtside Denver Nuggets tickets. This causes their younger selves to forgive each other and remain friends. Stan also leaves Randy a gift of the strain of marijuana Randy gave him in the future. Randy synthesizes it into a new marijuana strain, which he gives away for free. The marijuana causes everyone in town to forgive each other for the way they acted during the pandemic, as well as everyone in the world, including the protesters at the 2021 United States Capitol attack, and LeBron James who refuses to make Space Jam 2. In the future of the new timeline, everyone's lives have changed for the better (with Shelly, Sharon, and Kenny alive) except for Cartman, who is now an alcoholic homeless man on the street.