By the end of Episode 11, the U.S. government, led by a frantic Kyle, has set up a giant dome over Imaginationland, intending to detonate a neutron bomb to destroy everything inside—including the boys’ friend Butters Stotch, who was trapped there at the end of Episode 10.

picks up in the aftermath. Kyle Broflovski is trapped inside the radioactive, smoldering ruins of Imaginationland with a cynical, chain-smoking Tweek Tweak. Meanwhile, Cartman—believing Butters is dead from the nuke—panics, realizing he will have to literally "suck Butters' balls" unless he resurrects a loophole.

On the human level, the story begins with a mundane crisis. Ms. Garrison announces that a lice outbreak has occurred in the class. To determine who is infected, the school nurse conducts a hair inspection.