The Simpson family visits a young children's theme park for Maggie, but it's not much fun for the rest of the family. While there, Lisa bonds with a small lamb. They return home to find a huge Flanders family reunion going on next door. Homer is jealous, because Ned did not invite him. He vows to throw a BBQ of his own. Marge serves lamb for dinner, forcing Lisa to think about her little friend. She says she will never eat lamb again and she goes on to declare herself a vegetarian. She can't bring herself to dissect worms in class either and she even questions cartoons on TV. She wishes that Homer would serve something other than meat at his barbecue. Principal Skinner shows a propaganda film from the meat council, which makes her angry. She crashes Homer's party and steals the pig. Homer and Lisa refuse to talk to each other and Lisa leaves home in disgust. She finds no support from anywhere else; that is, until she talks to vegetarian Apu. He introduces her to Paul and Linda McCartney, vegetarian activists. The three of them give her a lecture on tolerance and then Apu performs a Beatles' song for them. Homer tracks her down and apologizes to her and she admits that she was wrong, too. The song "Maybe I'm Amazed" plays over the end credits as a pig flies through the air.