Billy's brain switching machine goes haywire (with a little help from Squatt & Baboo), causing his & Kimberly's minds to swap bodies! Hilarity ensues when Billy as Kim, and Kim as Billy, spend a few days in each other's shoes... literally! Will the popular & perky Kimberly learn a lesson from being brainy & beguiled Billy, and vice versa? Probably not. Also, the Genie monster rubs our heroes the wrong way.