Marge,Lisa and Bart are recaptured, Leaving Homer as the only free Simpson. Homer returns to Springfield to save everyone. A bomb is lowered down into the dome and the springfieldians attempt to escape up the wire holding it, but Homer knocks them all back down sliding down it to rescue them. He and Bart then take the bomb and ride a motorcycle up the dome where BArt throws it out of the small hole at the top/ The dome explodes and collapses but Homer and Bart outride it to the bottom before they fall. The bad guy politician (I forget his name) then tries to kill Homer but Maggie saves him by dropping a rock on the guy. Homer and Marge reunite and everyone lives happily ever after.