The show starts off with the build up from last season's cliffhanger revolving around Cartman's paternal origins. However, just as it seems they are about to get on with the second half of "Cartman's Mom Is A Dirty Slut," they do a 180 degree turn-around and reveal that for April Fool's Day they will be showing Terrance & Phillip in "Not Without My Anus."
Picks up from Episode 113Who is Eric Cartman's father? Dr. Mephisto knows, and is just about to reveal the information when he is shot, and must be rushed to the hospital. America's Most Wanted comes to South Park and there is a big snowstorm, creating a tight situation. Meanwhile, Liane Cartman seeks help in high places to see if she can get a retroactive abortion.
The school counselor, Mr. Mackey, lectures Mr. Garrison's class on how drugs are bad . He passes around some marijuana so the kids will know how it smells, but the sample gets lost and the school fires Mr. Mackey. Meanwhile, Ike is going to have his Bris, but when the boys find out what that actually means, Kyle tries to save his little brother from the ceremony.
The Booktastic bus is in town and soon everyone finds out that Officer Barbrady can't read. He is whisked off to school with the boys so he can save his job. While he's there someone in South Park is having sex with the town's chickens and only Officer Barbrady with his new deputies Kenny, Kyle, Stan, and Cartman can stop them!
While the kids are playing dodgeball in Chef's gym class, Kyle gets a severe nosebleed. He is taken to the nurse's office, which is widely regarded as a horrific place by the students. Kyle discovers the reason: the nurse has a stillborn conjoined twin fetus attached to her head. Kyle's mother hears about it and decides to make the town more aware of the nurse's condition. During this crusade, South Park Elementary is invited to compete in the state dodgeball finals in Denver.
Mr. Garrison assigns the class to ask Vietnam veterans they know about their experiences. The boys go to Jimbo and Ned, who now have a hunting show opposite "Jesus and Pals." Their story is so outrageous, Mr. Garrison fails them for cheating. The boys get seek revenge by sending Jimbo and Ned phony videos depicting the Mexican Staring Frog of Southern Sri Lanka, which causes any one who gazes upon it to become catatonic.
Ms. Crabtree's bus is stranded on a snowy cliff, and she go and find help. She warns the children that if they leave the bus, a big, scary monster will eat them. While on the bus, the children have flashbacks to vignettes from previous episodes, except that this time everything ends up involving ice cream.
It's summer in South Park, but with Colorado's new ban on fireworks, nobody is having fun. Jimbo and Ned go to Mexico, hoping to smuggle fireworks over the border. However, when Jimbo and Ned are busted with their contraband, the town is forced to light the worlds largest snake for South Park's big celebration. Meanwhile, Mr. Twig has gone missing, resulting in Mr. Garrison seeking psychiatric help.
The Sundance Film Festival moves to South Park after its original locale has turned from a quaint mountain town into another Los Angeles. At first, the town is happy to have all the people there boosting the local economy, but the Hollywood types start to impose. This is most harmful to Mr. Hankey, who has to live in the sewer when it's not Christmas. All the extra waste has disrupted his environment, causing him to slowly die. Kyle convinces him to come to the surface to confront the festival chairman.
Shelly gets chicken pox and has to be hospitalized. The doctor explains to Mrs. Marsh that it can be worse for children when they get older. She decides that Stan should get it while he's young, so she convinces the other parents to get all of them infected by sending Stan, Cartman, and Kyle to Kenny's house for a sleep over, since Kenny already has it. Meanwhile, Kyle overhears his mother on the phone talking about the plan and decides it's time to get even.
Mr. Garrison takes his class to the local planetarium for a field trip. Cartman leaves to audition for a Cheezy Poofs commercial outside. The rest of the class ends up being hypnotized and wanting to go back to the Planetarium. Mr. Mackey discover the secret of the planetarium and tries to stop the evil plan.
Wendy wants to set up Bebe with Kyle, so she ask Stan if the four of them can play "Truth or Dare" in his clubhouse. However, Stan doesn't actually have one, so he and Kyle start to build one. Cartman and Kenny are excluded and they decide to build one themselves. Meanwhile Stan's parents are facing the troubles of divorce.
Its the annual Cow Days festival, but the cows themselves are not interested in the event as they have become transfixed on a memorial statute. The cows relocate the statue but the town thinks that their two tourists are responsible. Meanwhile the boys want to purchase some Terrance and Phillip dolls and to get the funds they enter Cartman into a bull riding contest; but a freak accident during practice results in Cartman believing that he is a Vietnamese prostitute.
Goin'Down To South Park chronicles the history of South Park, as told though interviews by Trey and Matt, and several other members of the South Park crew. This documentary features many clips from previous episodes, as well as some of Matt and Trey's earlier works such as "The Spirit of Christmas (Jesus vs. Frosty)", "American History", and many more.
Mrs. Marsh's monthly visitor, Aunt Flo, gives Stan a goldfish for a present. Stan thinks it's spooky, but his mother makes him graciously accept it. The fish begins tohug people and his Mother believes it to be Stan, not the fish. Meanwhile, there is another Cartman walking around, who is an alternate version of his normal self walking around South Park. They soon come to realize that all the trouble is coming from the Indian Burial Ground pet store, and they set out to stop it.
The boys go to Nebraska to spend the holidays with Cartman's grandparents. Cartman's uncle Howard has to join the family dinner via satellite since he is in prison. That night, he breaks out with the help of his cellmate, Charles Manson. The boys go to the mall to see Mr. Hankey, but Kyle discovers that "Mr. Hankey" is a fake and all hell breaks loose. Meanwhile the cops see Manson and the chase begins.
To keep the school board from firing him for incompetence, Mr. Garrison assigns group oral reports to his class. The boys are put in a group with Tweek, the jittery son of a coffee shop owner. Tweek suggests doing the report on the underpants gnomes that steal his underwear. Meanwhile Mr. Tweek is offered 0,000 by Mr. Postum, who wants to turn his store into a "Harbucks" franchise. Mr. Tweek rejects the offer, and that night suggests that the boys do their report on how large corporations try to push out small business. Mr. Tweek writes the report himself and gives it to the boys. The board likes the report and uses the boys to put up a proposition to keep Harbucks out of South Park. Meanwhile the boys seek help from the underpants gnomes to teach them about big corporations.
Kyle falls into an ice hole and when Stan comes to rescue him, they find a frozen man embedded in the ice. The boys pull the ice man out, Mephesto takes the ice man back to his laboratory to thaw him out. He discovers that the ice man has been frozen since 1996. The government wants to get him for their own experiments, but Stan and Kyle free him, so the government hires Steve Irwin (from "Crocodile Hunter") to track him down.