Arthur Makes Waves

Summary
The community pool is closed for repairs, so Arthur and D.W. accept an invitation to James' pool. Then they discover that his older sister is Molly, an old nemesis of Arthur's.

Plot
Buster was describing Molly and Arthur's rivalry through ancient times with the Tough Customers and Arthur's friends as cavemen, the Wild West days with the Tough Customers and Arthur's friends as farmers, and the days of your grandmother and grandfather with the Tough Customers and Arthur's friends in their 50s clothes, when suddenly, he got a message, hence the title card.

After the title card, when Arthur and D.W find out that the community pool is closed for repairs, they try to find other places to cool off. They try the Tibbles' pool, but it was loud and the pool popped. Next, they tried Muffy's pool, but Arthur's foot gets hit. Then they try the Senior Center's Pool, but it was full of ladies and the water was hot. Finally, they try the library since it has air conditioning until a kid coming out of the library tells them the air conditioner is broken.

They soon give up all hope, but then they go to The MacDonald's pool. That's when they discover James' sister is Molly. At first, Molly insults Arthur and makes one side of the pool for herself, and one side of the pool for James, D.W., and Arthur. Eventually, Molly befriends Arthur and D.W., but they can't get seen together or they will be mocked by their friends. They almost get busted on many occasions, but when Slink and Brain see them walking off together, it goes over the edge.

Buster, Francine, Muffy, and Brain (Arthurs best friends), and Binky, Rattles, and Slink (Molly's best friends) decide to do something about them and go to confront them at the MacDonald's pool, only to find Molly there. The friends think they may have stopped any sort of friendship from forming between Arthur and Molly, but are wrong as Arthur and D.W. hid away from plain sight before the group of friends arrived and Arthur and D.W. eventually head off towards the community pool.

Major characters

 * Molly MacDonald
 * Arthur Read
 * D.W. Read
 * James MacDonald

Minor characters

 * Francine Frensky
 * Buster Baxter
 * Alan "The Brain" Powers
 * Muffy Crosswire
 * Rattles
 * Binky Barnes
 * Slink
 * 4th Grade Male Rabbit
 * Grandma Thora
 * Tibble Twins

Background characters

 * Mrs. MacDonald

Trivia

 * This is one of the episodes that focuses on water. The others being The Shore Thing, Water and the Brain, D.W. All Wet, Swept Away, and Feeling Flush.
 * This is also the first episode with Molly and Arthur as friends.

Episode connections

 * James made a reference to the episode "Kiss and Tell" where he asked D.W. if he wanted him to kiss her again.

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