While watching the Itchy & Scratchy parade, Bart encounters Chester J. Lampwick, who claims that Roger Meyers, Sr., stole the Itchy character from him. As proof, Chester produces an old cartoon reel of his original Itchy from 1919, but after he shows it to Bart and Milhouse, the projector melts the print.

Bart and Chester pay a visit from Roger Meyers, Jr., at Itchy & Scratchy Studios, where Chester asks Meyers for $800 million in damages. When Meyers kicks them out of the studio, they hire Lionel Hutz to handle the case in court. Just as Chester is about to lose his case, Bart produces a rare pen-and-ink Itchy drawing and proves that it predates the first Meyers cartoon. the court rules in Chester's favor, and Itchy & Scratchy Studios is shut down.

Now forced to watch boring cartoons, Bart and Lisa work unsuccessfully to strike a deal between Meyers and Chester. Meanwhile, Lester and Eliza, two children who bear an uncanny physical resemblance to Bart and Lisa, bring and end to the stalemate by exposing the U.S. Postal Service's plagiarism of another Roger Meyers, Sr., character. After receiving a sizable settlement from the government, Itchy & Scratchy Studios reopens and is soon back in business.