In the opening, Kang hopes to speed up an exceedingly slow and boring baseball game, but ends up destroying the universe when the baseball players go so fast, they turn into a killer vortex which sucks up the universe, even God. When everything was sucked up by the baseball players, Kang places a post-it note revealing the title of the episode.
Bart winds up in a coma after attempting to jump out of a window into a swimming pool. The family takes in a robotic boy, named David, who quickly proves to be a better son. Bart wakes up from his coma and competes against David for the affection of the family. However, Bart is dumped on a road by Homer. When Bart finds a group of old robots, he steals their parts and becomes a cyborg. He returns home, saws David in half with a chainsaw, and does the same to Homer. Although the family is now together again, Homer is angry that he has to be fused with David's lower half. Suddenly, the whole scenario is revealed to be a dream conjured by Homer's demonically possessed mind as he is being exorcised.
Men from Springfield arrive at Mr. Burns' mansion to go hunting. Unbeknownst to them, they are the prey to be hunted and broadcast on television. Homer manages to survive the night while the others are killed, but Burns closes in on him in the morning. Just as he is about to be shot, Burns and Smithers are knocked out with frying pans by Marge.
The citizens of Springfield dress in their Halloween costumes for a costume contest. The winner is declared to be a strange old witch. When given the award and asked who she is, she is forced to admit that she is a real witch. As a result, her reward is rescinded because she is not in actual costume. In anger, she turns everyone into their costumed characters. The only person who can reverse the spell is Maggie, who was costumed as a witch. Maggie turns them all into pacifiers with their normal heads and flies off on a broom.