Arthur and the gang head to the beach for some fun building sandcastles. Meanwhile Buster develops an acute fear of germs and begins to isolate himself from his favorite things - including his friends.
Timmy and Tommy miss Grandparents' Day and desire to do something nice for their grandmother, who is also their legal guardian. With some help from D.W. and Molly, they hope to improve their rambunctious manners.
Vicita Molina has lost her favorite book - a lovely South American tale of friendship and courage in the Amazon jungle. Everyone knows that elementary school is way too early to start thinking about college - except Prunella.
Fern receives the latest phone for simple communication, but becomes addicted to the appliance. Meanwhile Brain was held back in kindergarten and doesn't want his friends to know about it.
D.W. tells her friends that she's a fantastic skater. The truth is, with Emily's skating party coming up, she can barely stand on ice! Accused of being spoiled by her friends, Muffy sets about to prove them wrong.
Matt Damon guest-stars in animated form as the host of a new series, "Postcards from You." When the Oscar-winning star puts out a call for homemade videos for his show, Arthur and the gang rush to film their lives. Mrs. Molina is teaching a dance class for kids, and it makes for some unlikely dance pairings - will anyone survive the class?
There's nothing wrong with that... is there? Everyone loves the new "Top Supermarket" reality series on TV - everyone except Arthur. So when Buster stops watching "Bionic Bunny" to watch this popular new show, Arthur fears their friendship is over.
