When Frank and Joe Hardy go to Kids Day at the King Arthur Faire in Bayport, they run into Chet Morton. Chet won the Junior Joust competition and now has a ticket to a real jousting competition until the ticket goes missing. It is up to the Hardy boys to find the missing ticket and see if there is a rogue knight on the loose.
Embarking on a class trip to Bayport Bear Park, Frank and Joe join in an exciting scavenger hunt before learning that the prizes slated for the winning team have been stolen or destroyed by an unknown culprit.
Attending a science club field trip to the Bayport Museum of Natural History, Frank and Joe visit a fossil dig on the museum grounds where Tico and Aisha fight over which of them discovered a dinosaur tooth.
Frank and Joe Hardy help their friend Phil build a robot for Bayport Elementary's annual science fair, but when the robot goes missing the morning of the fair, Frank and Joe must investigate and find the culprit.
Hoping to win the pizza party grand prize on Field Day at Bayport Elementary, Frank and Joe Hardy investigate clues to discover who has sabotaged the events by ruining rackets, tangling jump ropes, and flattening balloons.