When Francine makes fun of Fern, she draws a comic humiliating her, which everyone finds amusing. Other comics about her are drawn. During the school carnival, those teasing her are convinced by Mrs. MacGrady to dump green slime on her. As they prepare to do so, they realize how much they hurt her feelings.
Arthur and Buster have to work with Binky on an art report, but they believe he will make them do all the work. He wants to do it on an abstract painting he believes is hanging sideways. To avoid embarrassment, Arthur and Buster make an agreement with him to do separate reports. Ironically, he is the only one who does any of the work and turns out to be correct.
Arthur's luck begins to change after he finds a pencil right before the stop of a rainstorm. After several lucky breaks, he and his friends are convinced that it is lucky. As it gets shorter, he is more conservative with it. Even with an upcoming history test, he won't let anyone use it, not even himself.
D.W. doesn't get along well with Kate and is sent to her room for ten minutes after threatening to pinch her. She thinks that her parents only love Arthur and Kate. While she watches Kate for the rest of her punishment, she realizes that she has been a horrible sister.
Binky rips his pants in class, revealing his underwear. Arthur can't stop laughing every time he thinks of it, but he's getting nightmares in which he doesn't have any pants. He tells Buster about this, who tells everyone else, which embarrasses him. Inevitably, he does rip his pants and has to deal with it.
Francine goes for horseback riding lessons and her sister, Catherine, has to bring her there. Catherine is better than Francine! Feeling over shadowed by Catherine, Francine considers quitting but returns and remembers why she wanted to take horseback riding in the first place.
Buster gets a cat down from a tree with his ice cream and his mother publishes a story on it. When people start calling him a hero, this goes to his head and he starts acting important and retells the story with embellished details. Arthur, Francine, and the Brain make a fool out of him to humble him, but he ends up saving Arthur and Francine from a runaway piano.
D.W. is still playing her "Crazy Bus" CD (since "Buster Baxter, Cat Saver") and Arthur is already annoyed by it. She surprises him with four tickets to "Crazy Bus Live". He is embarrassed to be there but finds Buster enjoying the show. When the CD goes missing, she accuses him of taking it, but their parents have done so by mistake.
Binky has a night light. He tries to go without it when Arthur has to spend the night because his parents are stuck out of town. When Arthur finds out about it, he believes Arthur may use this against him, although Arthur isn't particularly interested. Even so, he eventually musters the courage to tell everyone before Arthur does.
The school band has a recital on Friday. Everyone except Arthur is worried and practicing. He is confident that he knows everything well enough until a nightmare makes him worry he may miss a note. In a subplot, D.W. has hiccups that won't go away.
Francine and the Brain have an argument over soccer practice that carries into class and through the next match. They may not make it to the playoffs if the argument continues. Arthur uses D.W.'s idea of writing an early letter to Santa to resolve things between them with fake apology letters.
After school, Arthur is supposed to take the bus to the public pool for his swimming lesson, but he falls asleep and misses his stop. Then he ends up at the edge of town but luckily, the bus driver helps him find his way home.
Arthur has a to-do list for the summer, but he can't find it and summer's nearly over. He finds out everyone else had a great summer. He finds his list and D.W. accidentally helps him realize that he did all the things on it and had a great time too.
Mr. Haney gives Arthur an envelope to give to his mom. He is worried about its contents, thinking that it's about him, so he comes up with a way of giving it to her without her opening it. It turns out to contain Mr. Haney's tax documents.
Arthur and D.W. are planning a surprise party to show their appreciation for Grandma Thora. She unexpectedly shows up early when her car breaks down and they must finish their last minute preparations without her noticing.
Fern's mother wants her to invite some girls over for a slumber party to which she reluctantly agrees. Everyone thinks she is boring and bring their own entertainment, but she later manages to impress them with her detective skills.
The Brain and Francine use fake love notes to get revenge against Muffy after she puts them down at the science fair. Their joke has unintended consequences and they must fix it before things get worse.
D.W.'s overzealous safety patrolling and whistle blowing is annoying everyone. Arthur and his friends worry she may ruin the upcoming soapbox derby. During it, she finds herself in an unsafe situation when she is stuck at the top of a large pine tree after she climbs it to get a better view.
Arthur keeps losing at the new "No Guessing!" board game and other things as well, so he starts cheating to win. His friends are annoyed by his "sore winner" attitude and use Binky to make him lose, because Binky has no qualms about cheating.
Arthur and the Brain are afraid of the new crossing guard who charges them $10 per trip and will send his goons after them if they don't pay. They try to figure out ways to circumvent crossing the intersection before they realize his true intent.
Arthur and D.W. use a thesaurus to aid in calling each other names until he calls her "Dora Winifred" and she is upset. She later has a strange dream with him, Walter (from "D.W.'s Deer Friend"), and the Thesaurus.
Arthur, Binky, and the Brain find a key in the grass while looking for a baseball. They each think it's for something they would like and argue over who gets to keep it before they find out what its real use is.
In the latter half of this season, possibly in an attempt to conceal Buster's absence, there were more episodes that focused on characters other than Arthur and his family, such as Francine, Sue Ellen, and, most notably, Fern.