Part 1: The hamsters that power Sector V's weapons suddenly decide to go on vacation, leaving the Treehouse powerless! Meanwhile, the Delightful Children from Down the Lane look for villains to attack Sector V, so they send an old lady named Gramma Stuffum, who is fixated on fattening kids, to Sector V's powerless HQ. Part 2: The Kids Next Door find a new enemy in the dental hygiene-obsessed vigilante, Knightbrace after he attacks Numbuh 3 on the way back from a trip to the candy store.