Sue Ellen and her friends continuously lose against an anonymous player on an Internet game, "Virtual Goose". When she finds herself obsessed with winning against that player, she makes a promise not to play for a week.
Arthur and his friends stop playing "Virtual Goose", due to the fact that D.W. always wins, and move onto "Virtual Goose v5.0", a six-player multiplayer game where only one will win. The Brain loses and is challenged as to whether or not he could survive out in the wild, so he starts a camping trip. However, his friends, and even Mr. Ratburn, seem more interested in the internet.
Arthur gets a new piano teacher, Dr. Frederique Fugue, who is not only one of the best teachers but also one of the strictest. When he fails to practice sufficiently, Dr. Fugue "fires" him. Wanting to be rehired, he begins practicing the piece he was supposed to.
Buster is fundraising for the school band by selling chocolates, but he ends up eating some of them and giving others away. Since he does not have the money to pay for them he opts to make some, which he calls Buster Clusters, but they are only worth of being joke ones.
Prunella is excited to get her new monogrammed limited edition Henry Skreever book in the mail, but finds that it is in Braille. When she goes to the library to get it with words, she meets a blind girl named Marina, who is looking for it in Braille, and they become friends.
Kate and Pal can understand each other, but older people like the rest of the Reads can't. When Mr. Read can not find the figurine that goes on top of the wedding cake he made (which D.W. has mistaken for one of her "delicate" toys), Kate and Pal work together to get it on top of the cake before it gets to the wedding.
Muffy's dad is the new soccer coach and has the team do drills named after car parts. Muffy is not enjoying it since he is tougher on her and even makes her the goalie. The team doubts his coaching methodology until they finally tie a game.
The Young Person's Orchestra is going to hold tryouts at Lakewood Elementary. Everyone in the band thinks Binky is the best. However, since he can't perform well with his malfunctioning clarinet and can't afford a new one, he starts a scheme with the rest of the Tough Customers to get rid of music.
Buster thinks he saw a UFO, but no one believes him because he said that too many times. He borrows Muffy's telescope and finds a comet headed for Earth. No one believes him, but this time he has proof. They discover that the telescope is malfunctioning.
Francine is head of the new school newspaper after shadowing Buster's mom at work and taking a front page picture. She takes potentially embarrassing photos and publishes them out of context with embarrassing captions.
D.W. grabs the wrong backpack when it starts to rain at the community pool. She goes in search of the mysterious "_OM__ ___BLE" who she believes is a backpack thief. She uses things she found in it (i.e. a pair of pan pipes, an Eiffel Tower figure, a snowglobe, etc.) and concludes that "_OM_____BLE" wears the pipes to hide his sharp pointy teeth, and lives in a snowy section of China (the figure in the snowglobe). It turns out that the mysterious "_OM_____BLE" is none other than Tommy Tibble.
George has trouble reading and does not want anyone to think he is dumb. He takes Binky to be his mentor to teach him to be tough so no one will tease him, but realizes he was not cut out for being tough. He finds out that he has dyslexia and works his way around it.
D.W. is excited to be getting an allowance, but is discontent once she learns that Emily and the Tibble Twins have already been getting one and have more money. When she fails to get a bigger one, she pretends that she gets more than they do.
Arthur is overjoyed that D.W. lost her voice, but is not so excited when he has to do what she wants him to. When he discovers that she is better but continues faking, he gets his friends to come up with a plan to expose her lie.
Michelle Kwan is presenting the Athlete of the Year Award, but Francine is upset when it goes to Jenna. She rubs in the fact that she thinks she should deserve it by giving Jenna unwanted attention. Michelle Kwan guest stars as herself.
Arthur has a crush on his new babysitter, Sally. He is devastated when he discovers that she has a boyfriend named Corey. He tries to avoid her by going to Buster's only to find that she is there to babysit him.
Muffy's new marbles prompt Arthur and his friends to start playing marbles. Arthur signs up for a marbles tournament after he gets trained by Grandma Thora. When he discovers that he has to compete against her in the tournament, he plays poorly on purpose, but she loses first when she finds out what is happening.
The Brain does not believe in superstitions and goes on to try to prove this by doing things superstitiously believed to bring bad luck, like breaking a mirror. Counter to his hypothesis, a streak of bad luck strikes.
This season is the first and only one to feature Justin Bradley as the voice of Arthur, taking over from Michael Yarmush whose voice matured in 2000 (season 5), the first season to be animated with digital ink and paint, allowing for more color palettes and clearer picture and the first season where Samuel Holden voices Timmy Tibble instead of Ricky Mabe.
When Mark Rendall took over voicing Arthur in the following season, he re-dubbed Bradley's dialogue for syndication, though it is retained in international airings and home releases.
This season is the last one to feature Steven Crowder as The Brain, Oliver Grainger as D.W. and Jonathan Koensgen as Tommy Tibble.
This season's end credits originally used a remixed end theme music, containing the original theme song mixed with Francine's "You Can Fly If You Try" soul music as well as D.W. chanting "Yeah, Mama!". It was replaced during U.S. second run syndication in the mid-2010s.