After eating piles and piles of Halloween candy, Bart, Lisa and Homer have nightmares that haunt them all night. Lisa dreams that the family goes on a trip to Morocco and buys a cursed monkey paw that grants its owner three wishes. By wishing for world peace, Lisa accidentally paves the way for an alien invasion by Kang and Kodos, who enslave the human race. Homer dreams that Mr. Burns steals his brain for a giant robot he's building. Due to an accident, Mr. Smithers is forced to sew Mr. Burns' head onto Homer's body, creating a horrific two-headed creature. Bart's dream, in which he has the power to read minds and affect people with his thoughts, seems less like a nightmare at first. But eventually, he realizes he's used his powers for evil and repents.