After Homer accidentally pollutes the town's water supply, Springfield is encased in a gigantic dome by the EPA and the Simpsons are declared fugitives.
Bart Simpson / Maggie Simpson / Ralph / Nelson / Todd Flanders / TV Daughter / Woman on Phone (voice)
Yeardley Smith
Lisa Simpson (voice)
Hank Azaria
Professor Frink / Comic Book Guy / Moe / Chief Wiggum / Lou / Carl / Cletus / Bumblebee Man / Male EPA Worker / Dome Depot Announcer / Kissing Cop / Carnival Barker / Counter Man / Apu / Drederick Tatum / Sea Captain / EPA Passenger / Robot / Dr. Nick / Wise Guy (voice)
Harry Shearer
Scratchy / Mr. Burns / Rev. Lovejoy / Ned Flanders / Lenny / Skull / President Arnold Schwarzenegger / Kent Brockman / Principal Skinner / Dr. Hibbert / Smithers / Toll Booth Man / Guard / Otto / Kang (voice)
Pamela Hayden
Milhouse Van Houten / Jimbo Jones / Rod Flanders (voice)
Tress MacNeille
Sweet Old Lady / Colin / Mrs. Skinner / Nelson's Mother / Pig / Cat Lady / Female EPA Worker / G.P.S. Woman / Cookie Kwan / Lindsey Naegle / TV Son / Medicine Woman / Girl on Phone (voice)