As Springfield's bicentennial celebration approaches, Homer wins the role of town crier in the city's parade. At school, Lisa writes an essay on town founder Jebediah Springfield, who, her research reveals, was a murderous silver-tongued pirate.

For her accusations, Lisa is banned from the Springfield Historical Society by its president, Hollis Hurlbut, and ostracized by the townspeople. She and Homer convince city officials to exhume Jebediah's body to prove that he had a silver tongue. However, when the body is exhumed, no tongue is found.

Lisa deduces that Hurlbut stole the tongue and confronts him. Hurlbut confesses, but explains that he only wanted to protect the image of the local hero. Lisa realizes that the myth of Jebediah is more important than historical fact and decides to keep the information form the public. She leads the parade as Homer rings his crier's bell.