Homer goes to Moe's Tavern with a new suit, but when he tries to pay for the beer, he finds out that his pocket has much old stuff, including an old roll of film.
After bringing the family, they realize why the film was never developed: because it was full of photos of young Bart and Lisa fighting.
Frustrated about the kids to the point of having nightmares, Marge and Homer take them to a psychologist, who tells them that Lisa is smart and good while Bart is dim and evil.
Later, Ned finds his Grandma unconscious and the Simpsons children gone, much to Homer and Marge's despair.
Homer tries to bend a tree to save them, but the branch he is holding snaps, catapulting the kids back to the Simpsons' house into the clown bed, which falls apart.
Dr. Hibbert tells Ned his grandmother survived, and Moe calls Homer "Father of the Year."
Club gave the episode a B−, saying "for all the various comic and satirical uses they’re put to, Bart and Lisa can still be effective as characters when the show reminds us that they’re still just kids.