On Halloween, Bart, Lisa and Maggie sit in the treehouse and tell scary stories, while Homer eavesdrops on them.
The Simpsons move into an old house, wondering at its low cost. Their questions are answered when the walls begin to bleed and objects begin to fly through the air, and Lisa senses an evil presence in the house. There is also a portal to another dimension in the kitchen. Marge expresses the desire to leave, but Homer asks her to sleep on it, due to the cost of buying the house. That night, the house possesses Homer and the children, manipulating their minds and making them chase each other with axes and knives. Marge unlike the others however, is instead using her knife to spread mayonnaise on a sandwich and intervenes, breaking the trance. Afterwards, Bart discovers the source of the haunting - a Native American burial ground hidden in the basement. After the Spirit of The House threatens them again, Marge loses her patience and confronts the house, demanding that it treat them with respect during their stay. The house thinks it over, and eventually opts to destroy itself rather than live with the Simpsons.
The Simpsons are in their backyard having a barbecue when they are abducted by extraterrestrial life forms (specifically Kang and Kodos). The aliens explain that they are taking the Simpsons to their home planet on Rigel IV, "a world of infinite delights," for a 'feast'. En route they present the family with enormous amounts of food and watch eagerly as they gorge themselves, then check their weights, being particularly delighted at Homer's mass. Suspicious of the alien's intentions, Lisa sneaks into the kitchen and finds a book titled How To Cook Humans. She takes the book and shows it to the aliens, who explain to her that part of the title was obscured by space dust, which they then blow away to reveal the title How To Cook For Humans. Lisa, skeptical at this, blows off more space dust, revealing the title to be How To Cook Forty Humans. The aliens blow off the last of the space dust, finally revealing the real title How To Cook For Forty Humans. Enraged at Lisa's mistrust, they return the Simpsons to Earth, explaining that Lisa ruined the family's chance at paradise on the aliens' home planet. Homer and Bart agree with the aliens, but Marge tries to explain to them that Lisa was just concerned for their family and didn't know better. Even she agrees that Lisa sometimes needs to tone down her attitude and just ask.
Lisa reads "The Raven" by Edgar Allan Poe. In this adaptation, Bart is depicted as the raven, Homer finds himself in the role of the poem's lead character, while Lisa and Maggie are seraphim. Marge appears briefly as a painting of Lenore. James Earl Jones narrates.
The episode then returns to the treehouse and Bart, Lisa and Maggie, who are not frightened by any of the stories. They climb down from the treehouse and sleep peacefully the whole night. Homer, on the other hand, lies in his bed terrified. As he notices a raven outside the window similar to the one from the poem, Homer hides under the sheets and exclaims that he "hates Halloween".