After viewing an Itchy & Scratchy marathon on television, Bart and Lisa head downtown with their father for the big Itchy & Scratchy Day parade. Despite their best efforts to get a good view of the event, the threesome end up with a terrible vantage point. Irked, Bart decides to follow the parade, and ends up in a rundown part of town. He encounters an embittered old bum, Chester J. Lampwick, who tosses vegetables at the Roger Meyers, Sr. float. Chester claims that Meyers, Sr. stole the Itchy character from him. In fact, Chester claims he invented the entire concept of cartoon violence. As proof, Chester produces an old reel of his now-long-forgotten cartoon shorts. Bart is amazed by what he sees. He tells Chester that he stands to grow very rich. But the film print catches fire in the projector and melts.

The pair visit Roger Meyers, Jr. at the Itchy & Scratchy studios. Chester asks Meyers for 800 billion dollars in damages. He and Bart are almost immediately thrown off the premises. Left with little choice, Bart and Chester hire Lionel Hutz to handle the case in court. But without any evidence to support the claim, Hutz is unable to make much headway. Bart suddenly remembers the existence of a rare pen-and-ink Itchy drawing for sale at the local comic book store. He borrows money from Homer and bring the artwork to court. Bart proves that the drawing was made in 1919, nine years before Roger Myers produced the first Itchy & Scratchy cartoon. The court rules in favor of Chester, and Myers is ordered to pay a restitution of 800 billion dollars.

The Itchy & Scratchy studios closes its doors, forcing children to watch boring, unimagi-native cartoons from the 1970s. Bart and Lisa decide enough is enough. But their attempts to arrange a deal between Myers and Chester fails. Marge encourages the children not to give up, pointing out their many past success stories. But before they can save the day, two other young children–who resemble Bart and Lisa in many ways—bring an end to the standoff. The Itchy & Scratchy studios goes back into business.