Stan Marsh and Kenny McCormick are waiting at the bus stop when Kyle Broflovski tells them that he has tickets to the Lion King on stage. Stan and Kenny are a bit disappointed, but Cartman then appears and tells them some grand news. He tells them that "shit" would be said on Cop Drama that night. Kyle is the only one who feels that the marketing ploy is stupid. Later, Kyle asks Butters if he would like to go with Kyle to see the Lion King but Butters promptly declines. His parents want him to watch Cop Drama with them so that he doesn't take the word "shit" the wrong way. Then, the whole town returns to their homes or to the bar to watch the show. Finally, upon the conclusion of the Cop Drama episode, a character says "shit", causing everyone to celebrate. Kyle missed it and is annoyed that his friends think it's such a big deal. He remarks that it's still the same world and opens the front door to find that it's raining frogs to his dismay.
The next morning, Channel 4 News reports on the Cop Drama phenomenon and also reports on a mysterious virus that makes people vomit their intestines. At school, the students learn about what verbal ways they can say "shit". Cartman is astonished thinking shit is a whole new word to Kyle's dismay. Kyle vows that he will prove that it isn't a new word by looking it up in the encyclopedia. Mr. Garrison also teaches the Kindergartners how to say shit and "Shitty shitty, fag fag." All across the town, people now are using the word "shit" more and more. This awakens the Knights of Standards and Practices.
Mr. Garrison calls somebody a fag, making it a point that he is gay and that he can say "fag". Stan and Cartman then say that "shit" isn't fun to say anymore because everyone says it. Kyle then frantically tells them that the word "shit" might have something to do with everyone vomiting their intestines. Stan and Cartman don't believe him and Kyle, then, explains that people started dying after they said "shit" on television and that the word "Shit" first appeared in English around the time of the black death. The boys go and ask Chef. Meanwhile, at the HBC Headquarters, workers complement the head of the company for his "shit" idea and the head of the company announces their next marketing ploy. They are going to say "shit" twice. Chef and the boys, go to the library and learn that the virus going around is spread by saying "shit" as it is a curse word. They also learn that the virus is actually the plague. They go to warn HBC of this but they disregard it and make Chef and the boys leave. They also reveal their latest marketing ploy, which is to air all their sitcoms live but say "shit" in front of their written dialogue. One of the knights of standards and practices attack HBC and is killed, in the process giving Stan a stone called the Rune Stone of Undoing. Chef and the boys go to the Excalibur Casino in Las Vegas to get help from the British in which the hotel and casino employees are pretending to be them during the Middle Ages. Then, a worker explains that saying the word once in a while is okay, but, saying it too often can lead to the plague.
Meanwhile, at the bar, everyone is getting sick of the word "shit" and are saying that the company is going to have to come up with a new word. Mr Garrison says they can say "Fag" and explains that you have to be gay or else you'll be bleeped. Jimbo says it unbleeped showing that he is gay, and Mr Garrison asks him if he wants to make out. On the set at HBC, The Knights of Standards and Practices try to stop the word of the curse (Shit). Everyone thinks it's part of the show. The boys learn that they have to defeat Geldon to save the world using the stone. Kyle defeats Geldon with the stone and then explains that everyone is saying "shit" too much and that they need to keep the curse words taboo. Kenny dies of the virus and Stan stops himself from saying "shit", saying "poo" instead. The episode ends with Cartman expressing his love for his friends.