Read 'Em And Weep (Crossover Version)

Lisa Simpson and Maggie Simpson are walking along when they come upon Tigger, who is selling books. Maggie takes a fancy to a book featuring a castle on the cover, but Lisa, noticing the dollar sign on the table, (thinking that it is expensive) disagrees. Upon seeing a box with a cent symbol on it, Lisa decides to buy Maggie a book that resembles an agonized face. Later that night Lisa reads the book to Maggie, causing clouds to swirl over their house and birds to fall out of the sky. Lisa closes the window and turns out the lights, leaving a terrified Maggie alone in the darkness. A strange, ominous glow appears in Maggie's room, and when she looks down to see what it is, she is attacked by an unseen force. The next morning Lisa makes breakfast for Maggie, who is now green and in a zombie-like state. After refusing to eat his breakfast, Maggie's head rotates 360 degrees and Maggie vomits a green fluid all over Lisa. The doorbell rings and Lisa answers the door to see Twilight Sparkle, dressed as a girl scout, selling cookies. Suddenly, a tentacle wraps itself around Twilight and pulls her offscreen. We now see that Maggie has tenacles and a beak coming out of her head. While Twilight clings for dear life on a cabinet under the sink, the monster in Maggie's head tears the skin and tail off of Twilight's lower body. She manages to escape into the area beneath the sink. She starts crying from the possible pain she's enduring or from fear or possibly for both reasons, but the tentacles emerge through the pipes and grab her again. The tentacles attempt to drag Twilight through the drain of the sink, crushing her body in the process. When she gets stuck, the tentacles use the garbage disposal to grind up her body, bringing her cries of pain and fear to an end. While the beak begins eating Twilight's mangled remains, a panic-stricken Lisa places a phone call.

The doorbell rings again and Lisa answers to find Goofy, a priest/exorcist. He is immediately vomited upon by Maggie, who he then tackles. Goofy struggles with the monster in Maggie's head and eventually succeeds in tearing it out. Maggie, now her normal color and minus the monster in his head, looks at her body and smiles happily. Unfortunately, Lisa, not realizing that Maggie has been cured, continuously hits Maggie with a shovel until she is a flat, bloody circle. Later, Lisa and Goofy stand at Maggie's grave, mourning her death. Before the episode ends, a tentacle comes out of Goofy's mouth, which he quickly places a hand over.