Cartman excitedly brags to the other boys that he is the first to reach puberty, since he's gotten his first pubes. However, it turns out that he bought them from Scott Tenorman for $10.00. Cartman tries to get back his money through various methods, but is always outwitted by Scott, losing an additional $6.12, being unable to attend a movie with the others, and being tricked into traveling all the way to Fort Collins in the process. Kyle tells Cartman that he should just accept his loss and move on because Scott is smarter than him, but Cartman persists in getting his money back. Ultimately, Scott lights his money on fire and Cartman starts screaming in rage and promises revenge. First, he tries to get his friends on his side, but because Cartman is the only victim, none are interested. Cartman's first major plan involves training one of Farmer Carl Denkins' ponies to bite Scott's penis off. He trains one to attack a scarecrow with a hot dog hanging from its pants. The pony doesn't bite it off the first time, and instead gives it a blowjob. Jimbo and Ned turn up, stating that the best way to humiliate Scott is to exploit his weaknesses. When they stake out the Tenorman house that night, Cartman discovers that Scott is a fan of Radiohead, and begins developing a scheme. However, Jimbo and Ned are distracted by the fact that Mrs. Tenorman is showing her breasts. They, along with several other men, are caught by Mr. Tenorman and run away.
Cartman's plan involves dubbing his voiceover that of the Radiohead members to make it appear that the band is telling Kurt Loder that Scott Tenorman is "totally not cool". This plan fails, and Scott further humiliates Cartman by showing the entire town a video of Cartman pretending to be a pig to get his money back. Cartman abruptly becomes a laughing stock in front of the whole town (Kenny even dies from laughing too much at the video). This finally sends Cartman over the deep end and he begins crafting a plan above and beyond anything that he originally had in store. He invites Radiohead to come to South Park to meet Scott (who, according to the letter, is dying from cancer in his butt) and asks if they are free "next Tuesday around 5". Stan and Kyle betray Cartman, warning Scott that Cartman is training Denkins' pony to bite off his dick. Cartman invites Scott to a chili cook-off, telling him that he can have a free pony ride at the event. Scott, who thinks he knows what Cartman's plan is, tells his parents that there's an abandoned pony at Farmer Denkins' ranch. His parents then go to the ranch in order to have the pony sent to an animal shelter. Scott decides to humiliate Cartman once again by having his friends collect public hair from all the kids in South Park and laces a pot of chili with them with the sole purpose of feeding it to Cartman in-front of the entire town.
At the cook-off, Stan and Kyle tell Cartman that this is the dumbest thing he has ever done, to which Cartman replies that once Scott Tenorman arrives, it won't be. When Scott does arrive, Cartman, "tries" to bring Scott over to the pony. But Scott tells him that he want's Cartman to try his chili first because he think he can win first prize, so Cartman obliges. Everybody is waiting for Cartman to get humiliated (except for Chef, who brought his own chili). Scott eats Cartman's chili first, and then taunts Cartman to do the same. When Cartman has eaten most of a bowl of Scott's chili, everyone starts to laugh before Scott begins to tell Cartman what he did. However, Cartman reveals that he already knew that Scott had laced his chili with pubic hair so he switched Scott's chili with Chef's. Cartman compliments Chef's cooking, claiming that he hadn't planned on the chili being delicious but that he had planned on Stan and Kyle betraying him and telling Scott that the cook off was a trap, shocking the pair. Cartman then explains that he assumed they would tell Scott that he trained Denkins' pony to bite off Scott's penis. But he reveals that they didn't tell Scott that Denkins also had a policy to shoot trespassers on sight. Knowing Scott would try to sabotage the pony, Cartman met with Mr. Denkins at his ranch and warned him that violent pony killers were spotted in the area. Also knowing that Scott wouldn't go himself out of fear of getting his dick bitten off, he assumed that Scott would mostly likely send his parents to do the dirty work. As a result of Mr. Denkins being on particularly high guard that night, when he saw Scott's parents on his property, he shot them both, killing them. A shocked town avert their eyes to Mr. Denkins who quickly defends what he did by pointing out that Scott's parents were trespassing and he had a right to defend himself. Cartman then reveals that he's not finished, explaining that he arrived at the scene just in time to see Denkins giving his report to Officer Barbrady and of course, steal the corpses. After a night of dismemberment with a hacksaw, Cartman says that he was finally ready for the cook off so he could personally tell Scott about the tragic and horrifying deaths of his parents, and of course, give Scott his chili. He concludes by asking Scott if he likes the chili he prepared for him, telling him that he dubbed it, "Mr. and Mrs. Tenorman Chili". Quickly catching on to what Cartman means, Scott reaches into the chili and pulls out his mother's finger with a diamond ring on it, realizing that Cartman really did just make him eat his own parents in a bowl of chili, vomiting in terror. Cartman then jumps up on the table and mockingly sings, "Nyah nyah nyah nyah nyah nyah! I made you eat your parents! Nyah nyah nyah nyah nyah nyah!". Stan and Kyle look on from the crowd, absolutely horrified at the situation unfolding before them. At that moment, right on cue (and exactly on Cartman's schedule), Radiohead shows up. They see Scott sobbing and mock him for being a "crybaby" and "totally not cool" and they leave Scott sobbing.
Finally, as Scott is crying over the death of his parents, Cartman victoriously licks the tears off of Scott's face, remarking that they are "yummy and sweet", as well as calling them "The Tears of Unfathomable Sadness." Kyle remarks to Stan that it would probably be best for everybody to never piss Cartman off again, to which Stan immediately agrees, both horrified by the lengths Cartman went to for revenge. The episode ends with Cartman in a Looney Tunes style circle saying, "That's all folks!".