Arthur Loses His Marbles (episode)

When Arthur discovers that Grandma Thora is a marbles champion, he trains with her so he can beat all his friends. And though Thora teaches Arthur everything he knows, she doesn't teach him everything she knows ... and it's Read versus Read in the first-ever Elwood City Marbles Tournament.

Trivia:

 * This is one of the few episodes that feature references to Star Wars.
 * When Buster said "Oh, the humanity!," that is referencing something the reporter Herbet Morrison said when he witnessed the Hindenburg Blimp crashed.