When Marge breaks her leg in a skiing accident, it's up to Lisa to run the Simpson household in her mother's absence. Lisa thinks she can handle the responsibility by implementing a structured plan and using fun management techniques like a "chore hat" from which her father and brother can randomly select a chore. Of course, Homer and Bart ignore Lisa's system and the house turns into a pig sty. Meanwhile, Marge is discovering the wonders of shiatsu massage as she receives foot, leg and hair rub-downs in the hospital. Lisa is so angry at Homer and Bart's lack of consideration that she decides to play a trick on them. With a little inspiration from the spirit of Lucille Ball, Lisa comes up with a way to trick Homer and Bart into thinking they have leprosy. Her trick works so well that Homer and Bart get sent to a leper colony in Hawaii courtesy of Ned Flanders. When Marge gets out of the hospital, she and Lisa track Homer and Bart down at the leper colony but discover that they don't want to leave.