Beavis & Butt-head watch the news about ah huge nuclear radioactive gas leak from a cargo train derailment, and it is called an apocalypse for 20 blocks. The duo mistake this for the actual apocalypse when everyone leaves their houses and they find they've got the whole neighborhood to themselves. They pillage the abandoned Maxi-Mart then proceed to Stewart's house. While Stewart's house is empty, the duo go there to takeover and make a huge disaster out of it, destroying many of the Stevenson's stuff, to make it cool. They even destroy Stewart's dead Grandmother's remains on the floor. Later, they see a woman (wearing a protective suit from the radiation) and they take off their clothes so they can have sex with her and to repopulate the human race. However, the woman leaves them and she tells her team that she found no one. They later on find a white trash house with plenty of guns to help them survive. Unfortunately, it belongs to one of their worst enemies, who soon arrives to take it back and does not appreciate having the duo in his home.
News show up and tell a tragic hit the Stevenson's home, not knowing it was Beavis and Butthead that did it.
This episode marks the official return of Harry Sachz, who supposedly died in Butt Flambé. Although it is unknown how he survived the gunshot. It's possible that this episode is non-canon or Harry might have a twin brother.