CAPTAIN UNDERPANTS returns! George and Harold, and their doppelgangers, Yesterday George and Yesterday Harold, have a good thing going. Two of them go to school, while the other two hide in the tree house and play video games all day -- then they switch! But when their malicious gym teacher, Mr. Meaner, morphs into Sir Stinks-A-Lot, the fun-loving four have to call on Captain Underpants to save the day!