Lisa, Bart and Homer eat loads of candy and Marge warns them that they will get nightmares. They ignore her, and each three have nightmares. Lisa dreams that the Simpsons buy a severed monkey paw, which can grant them wishes, but each wish has an unexpected consequence. Bart dreams that he has an ability to manipulate things with his mind. Everyone is compelled to carry out his orders, agree with his opinions, etc., in order to prevent him from using his ability on them. And Homer dreams that in an effort to create the ultimate worker, Mr. Burns transplants Homer's brain into a robot.