The gang is devastated after their tree house collapses.

Everyone in Arthur's chorus group is excited about their upcoming performance in Crown City. But when Ms. Krasny gets sick, she is replaced by Arthur's strict piano teacher Dr. Fugue.

Buster takes advantage of generous George, asking him for so many things. But George is shy and is afraid to tell Buster no.

Having landed a role for a class play, Arthur finds that he can't fit into his outfit. He and his friends team up to get him in shape.

When Muffy wants to take photos from the jungle gym with her new camera, she gets into into an argument with the Tough Customers, the school bullies.

Buster learns to care for plants.

Fed up with getting punished for Timmy's behaviour, Tommy asks D.W. to teach him good manners.

Mr. Crosswire brings Muffy to an opera.

Arthur's good grade streak slips when his mother takes a client and he fears she won't be around enough.

James invited D.W. and Arthur to swim at his house. Arthur is shocked to learn that Molly is James's older sister.

Grandma Thora takes in a stray dog that is extremely mean.

Prunella gets jealous when Marina joins yoga lessons with her and her mother.

Arthur's friends take his game against Brain in an interscholastic checkers tournament too seriously and he is frustrated with their unwanted support.

When a better soccer team comes to town, Francine and the Brain quit their old team to join them.

Emily makes up an excuse to keep the ball D.W. has found, but starts telling bigger lies to cover up the first one.

The Tibbles receive a new set of drums and want to perform in the Summer Serenade Festival, leaving D.W. to moan over not having her own instrument.

Arthur and Buster go to the park to investigate a rumor that tigers are loose there.

Binky discovers that he's allergic to peanuts.

Much to his horror, Brain gets a B Minus on a test.