Plot (Spoiler)
After a man in a chicken suit warns Peter that the world will end because of Y2K, Peter locks his family up in their basement on December 31, 1999. A nuclear holocaust then occurs, destroying much of the world and mutating, injuring, and killing many of the citizens of Quahog. The family then travel with the surviving citizens of Quahog to Natick, in hopes that the Twinkie factory survived; during the process, Stewie is exposed to the radiation and mutates into an octopus. However, upon their arrival, they find the factory to be deserted, and must survive alongside the citizens of the city in Natick (dubbed “New Quahog”). Peter is elected head of the town, but makes several fatal mistakes and is chased out of “New Quahog” alongside his family by an angry mob, singing “Left foot, right foot” the whole way out. The episode ends with a live action sequence involving Pamela Barnes Ewing waking up to find her husband Bobby in the shower. She tells him about the episode, which was a dream, thus retconning the entire episode, a parody of the Dallasepisode “Blast from the Past”.