The children are forced to join a choir sent to Costa Rica to perform against deforestation, but they end up lost in the rainforest and discover that the rainforest isn't worth saving. Meanwhile, Kenny falls for a girl in the chorus, but she is reluctant to pursue a long distance relationship.
Randy must solve the problem when citizens start spontaneously combusting. Meanwhile, Cartman plays Jesus in a "Stations of the Cross" play and ends up stuck on the cross.
When Chef gets engaged, the boys become increasingly concerned as he seemingly becomes a different person. Meanwhile, Cartman becomes the butt of several pranks by his eye doctor.
The town saves a species from extinction, but finds that they are an extremely annoying race that only Cartman can stand.
Stan, Kyle, Cartman, and Kenny pit Tweek and Craig against each other. Meanwhile, the school shop teacher, Mr. Adler, copes with the loss of his wife, who died in a plane crash.
A man in a panda costume is hired to teach the kids about sexual harassment, leading Cartman to sue Stan (and all the kids to sue the school) over claims of being harassed.
Cartman is stuck at home with Stan's sister Shelley as his babysitter while his mom is at a meteor shower party. Meanwhile, Cartman's cat, Mr. Kitty, is in heat and goes searching for sex with other cats.
At the meteor shower party mentioned in the previous episode, Stan is stuck in a basement with a group of nerdy kids from school who become important to him when the ATF stakes out the party, thinking that the attendees will commit suicide when the meteor comes.
On the night of the aforementioned meteor shower, Kyle, Kenny, and Ike go to a Jewish scout camp where Moses appears.
Nu metal band Korn guest stars in this episode where they are blamed for making Halloween immoral and the boys use Kyle's grandmother's corpse to scare the fifth graders.
Cartman's mom buys a vocabulary-building kit to help Cartman win the spelling bee. Meanwhile, Kyle falls for a homeschooled girl with overprotective parents.
The boys must save Starvin' Marvin from the government and a Christian group who cares more about converting people from third-world countries than giving them food and shelter.
During a Civil War reenactment, Cartman (as General Lee) leads the Confederate army to attack the Union soldiers across America.
Mr. Hankey hosts a Christmas musical, featuring South Park characters singing twisted renditions of classic Christmas songs.
Cartman and Kenny mistake a colon infection for their menstrual cycle, prompting Kyle to lie about "getting his period" and Stan to ingest hormone pills so he won't feel left out. Meanwhile, Jesus plans a New Years' party and is worried his father won't be there.
The boys travel to Arkansas to perform at a recorder concert. Meanwhile, Mr. Garrison confronts his father about not being sexually molested as a child.