Arthur is looking forward to having his friend the Brain spend an entire weekend at his house, but then the Brain shows up and starts acting a little too much like the perfect family member.
When Arthur and his friends buddy up to train for a race that will raise money for their school's literacy drive, Fern seems uninterested in winning or even improving her speed.
Arthur's Grandma Thora, a marbles champion, trains him for the first-ever Elwood City Marbles Tournament, but does not tell him that she will compete against him.
Arthur and his friends set out to make the world's largest pizza so that their feat can be recorded in "The Book of Incredible and Amazing World Records."
When Arthur fails to show up for his second piano lesson, his music teacher dismisses him. Now Arthur has to decide how much he wants to learn to play the piano.
When Arthur's soccer team gets a new coach who gives them brand new uniforms and lots of ice cream, it takes them a while to realize that he doesn't know how to coach soccer.