Editing Buster's Breathless

Arthur and Buster were hunting for the dangerous snig which Buster describes to the viewers as big-horned and that makes an "Aroo!" noise. Arthur also says that it's hard to find because it camouflages within the trees. Suddenly, they hear the noise and goes to see that D.W.'s not camouflaged and she needs to make the noise more scarier. So D.W. puts on poison ivy. Arthur and Buster are once again on the search of the snig. Buster's about to describe the snig again, but Arthur stops him. Then they hear D.W. again, and goes off to follow it. Suddenly, D.W. pops out roaring, freaking Buster out. Arthur sees the poison ivy on D.W. and he and Buster retreats screaming. D.W. is confused and goes after them.

Jane Read puts calamine lotion on D.W.'s spots and recruits Arthur to help distract D.W. At the Sugar Bowl, Buster greets Arthur and D.W. who claims to be Otis. Buster asks D.W. why she has a hockey mask on, and D.W. says she doesn't want to get hit in the face with a puck. Arthur translates saying she's got poison ivy and that people will run away from her. Buster begins to tell Arthur and D.W. about his bad cough back in the fall. Arthur and Buster were laughing at some old joke books when Buster starts having trouble breathing after breathing in too much of the dust billowing up from the books. Buster goes on to say that it sounds like he's trying to breathe through a clogged straw and demonstrates, only to sip away D.W.'s entire milkshake much to her annoyance. Arthur then remembers that Buster's mom came and took him to the hospital right away.

Arthur regrets showing Buster the joke books and blames himself for making his friend sick. At the hospital, Buster learns he has asthma, which will not harm his lifestyle in any way so long as he takes his treatment regularly. At school, Arthur tells Francine and Binky about Buster's cough and asthma, and Francine becomes worried that its a contagious disease. Buster then arrives and Arthur takes his math book and dusts it for him to be safe as they all begin to act strangely around him. Binky asks Buster if he gets to leave class because of asthma, and while he insists it's just to get his medicine Binky suspects it can get him out of class for a long time. After class, Buster goes to the nurse's office. Arthur, Francine, and Binky watch him take his medicine through an inhaler before being caught by Buster at the door. Arthur quickly covers it up and they run off to lunch. There, Arthur dusts off Buster's doughnut. At recess, Binky fakes an asthma attack to get sent to the nurse, but it backfires when he refers to it as "plasma" in front of Buster. At baseball practice, Francine still thinks asthma is contagious and runs away from Buster. Later, he announces he's cured. Francine is relieved she can't catch it, which makes Buster suspicious. Buster skips his appointment to keep his cover, which results in Buster having trouble breathing when they play a game of soccer with dusty brooms. Buster is rushed back inside to get his medicine and then explains to the nurse his friends have been treating him differently. Then Buster realizes his friends didn't understand his condition. Later, as part of a report project Buster decides to explain what asthma actually is to the class. He instructs them to imagine that they're really small and that they are inside his lungs, where Buster explains in this apparent fantasy that asthma is a reaction to breathing in too much dust or mold, and is not a contagious disease as Francine feared. He then snaps them out of the fantasy, and concludes his story by telling the class that he is still the same old Buster in spite of having asthma. With his story told, his friends finally calm down about his condition and all returns to normal at Lakewood.

Back in the present, D.W. reveals herself to Arthur and Buster. Then the Tibble Twins appear and confuse the poison ivy spots for chicken pox. D.W. tries to explain it's poison ivy, but they run away with D.W. chasing them, ending the episode.