D.W., Arthur's little sister, tells all about what it is like to be in preschool, including essential information about such topics as bathroom breaks, storing things in a cubbie, and sharing at play time.

When Arthur sees advertisements for the amazing doggy Treat Timer, he decides to earn enough money to buy it for his dog Pal. Arthur's purchase of a Treat Timer for his puppy, Pal, backfires when the device only frightens his pet.

Arthur's determination to prove he is responsible enough to have a puppy brings him a menagerie of animals to care for.

His friends tease Arthur when he gets glasses, but he soon learns to wear them with pride.

Even though her brother Arthur says she is too little to help with the upcoming wedding, D.W. proves she is just the right size when disaster strikes during the ceremony.

When Arthur and Buster try to take the bus to Arthur's swimming lesson, they fall asleep and end up in a strange part of town.

Arthur is not looking forward to Camp Meadowcroak, and when mysterious things start happening there, he decides to run away.

Unhappy with his nose, Arthur visits the rhinologist to get a new one.

Arthur finds everything about Halloween scary, including his little sister's costume, his morning snack, and the big house on the corner.

Arthur's wrong guess about the identity of the secret admirer sending him valentine messages leads to teasing by the other children, but clues in additional messages allow him to get his due.