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After burying the pet goldfish, Bart and Lisa came upon the grave of "William H. Bonney" in Springfield Cemetery. Lisa misinterpreted his tombstone's epitaph, "I dream of a world without guns," and used it as a successful rallying cry to make Springfield gun-free. He, along with other dead criminals, came out of their graves as zombies and went on a rampage killing people as they had no guns. Homer went back in time and warned the people not to get rid of their guns, but to shoot the graves, including Billy the Kid's.[2]