When Arthur's third-grade class competes at the Middle Ages Fair they lose at everything. Their only hope for victory is if Arthur can pull a sword from a stone.
Arthur is unhappy about going on vacation with his family, but he shows them how to make the best of a bad situation when they end up stuck in a motel because of rain.
When a parent group bans a series of scary books from the local public library, Arthur and his friends devise a plan to get their favorite books returned.
Muffy is so sure that Francine cannot be nice for an entire week that she bets her Princess Peach watch on it, and now it is up to Francine to keep her temper.
When Arthur's third-grade class goes hunting for fossils at Rainbow Rock State Park, his friend Buster actually finds one, and instead of turning it in Buster decides to take it home--but he soon regrets his decision.
Arthur and Francine are always dance partners when everyone square-dances in gym class, but Binky and Muffy start to think, and tell others, that the dancing partners are actually in love.
When Buster defeats the Brain in a math contest, he is chosen for the school mathathon. Crushed, the Brain says he's decided to become a comedian and declares Buster the new "brain."