On their way to Wanker County, the Bundys stop at the car wash, where their Dodge disappears.

Principal Skinner releases a weather balloon, but Bart turns it into an anti-Skinner prank. Principal Skinner is upset, so Bart's punishment is to help him log amateur astronomy sky coordinates. Bart gets up at 4:30 AM to assist Skinner. When Skinner steps away, Bart discovers a comet. The nerds of the school, super friends, soon embrace him. When they figure out that his comet is approaching Springfield and will annihilate the town, Professor Frink comes up with a plan to intercept the comet with a missile. Unfortunately the missile misses and destroys the only bridge out of town; the people of Springfield are doomed! The Flanders family let the Simpsons in their bomb shelter. The rest of the town asks Ned if they can come in as well. When the shelter is too full, one person has to leave, so they kick Ned Flanders out. Soon they feel guilty about it, so they all leave to die with him. The comet comes through the atmosphere and breaks apart due to all of Springfield's polluted clouds.