Apple is challenged to a fight by a grumpy Cheesesteak after Apple yells at Lemondrop, so he and Onion go on a quest to find the source of Cheesesteak's grumpiness by using the clues for a “chain reaction”. This quest starts from the hotel, then into a room, then into a kitchen, then into the sewers, then into another room, then into Edwards School. Song: "Classic Domino Chain Reversal Song"