Castles in the Sky

Summary
The gang's treehouse collapses, and architect Frank Gehry steps in to help them rebuild—if they can agree on a new design.

Plot
One day, during a snow-sledding race between Arthur and Buster, the tree house has been destroyed by snow. Later at the Sugar Bowl, Arthur and his friends are worried. Then a man named Frank shows up and offers to help the gang. Arthur and his friends come up with lots of different designs for their tree house, but Frank doesn't approve of them. Then they discover they like the original design better. So they started rebuilding their tree house. As Frank leaves, he gave them a picture of one of his building designs. That was before they discovered it was Frank Gehry.

Major

 * Arthur Read
 * Buster Baxter
 * Francine Frensky
 * The Brain
 * Frank Gehry
 * Muffy Crosswire
 * Binky Barnes

Minor

 * Bitzi Baxter

Cameo

 * Carl Manino
 * Jane Read
 * D.W. Read (as a baby)
 * George Lundgren
 * David Read
 * Bo Baxter
 * Wally
 * Oliver Frensky
 * Neil Lundgren
 * Alex
 * 4th Grade Male Dog
 * Kiefer
 * Leah MacGrady
 * Maria Pappas
 * Jenna Morgan
 * Fern Walters
 * Nigel Ratburn

Mentioned

 * Frances

Trivia

 * D.W. is only seen as a baby instead of her 4 year old self.
 * Irony: Brain said they liked the original idea better, but that's only because Frank rejected all their ideas.
 * Moral: Dont reject someones ideas so that your plain design is the best for your own personal benefit.
 * Special guest star Frank Gehry plays as himself.
 * Timeline: Buster references his first dinner with Harry from "Bitzi's Beau."

Episode connections

 * The name Frances appears in this episode. It's unclear who Frances is, but their name would be joined by a list of ten other unidentified students' names in the Season 13 episode, "Arthur's Number Nightmare."

Cultural references

 * The famous buildings shown are in "" by Antoni Gaudí in Barcelona, the by Frank Gehry in Los Angeles, and the  by Frank Gehry in Bilbao.
 * This episode's title is close to the same as 's 1986 film,.

Errors

 * When Francine is drawing the new treehouse on the stump, she mentions that Sue Ellen wants a pagoda; but in the Sugar Bowl when Francine shows the design to Frank, Sue Ellen has an art studio.
 * It is possible that Sue Ellen might have changed her mind or that Francine simply made a blunder while pitching her treehouse idea.

Production Notes

 * This is the first episode where Cameron Ansell voices Arthur Read.
 * This is the first episode where Cookie Jar Entertainment produces the series.