Lunch Lady and Betty have been fired but the Breakfast Bunch convinces them to return and stop the school's new superintendent and her minions from carrying out an evil plan for revenge.
Ollie the purple elephant is delighted to move into the McLaughlin family's New York City apartment but their cat, Ginger, is not pleased and devises a plan to send Ollie away with the circus.
While Farmer Joe is at the National Tractor Society Conference in Reno, his animals go on tour in a broken-down van, performing as the band called Punk Farm.
For having skipped the school field trip, Dee, Hector, and Terrence must join the mathletes team but as they are poised to beat the undefeated champions, secret crime fighter Lunch Lady discovers something strange about the opposing team.