Castles in the Sky

Castles in the Sky is the first half of the 1st episode of Season 9. It first aired on December 27, 2004.

Summary
The tree house collapses under the weight of snow of the roof. After meeting Frank Gehry at The Sugar Bowl, Arthur and his friends come up with different ideas to build a new tree house. The only design they agree on is the original, which they rebuild.

Plot Outline
There is snow on the ground and Arthur and Buster decide to have a sled race to the treehouse. When they arrive at the treehouse Arthur loses the race, but the treehouse collapses under the weight of all the snow. The rest of the gang soon meet at the Sugar Bowl to discuss the first day the treehouse was built and they then encounter Frank Gehry. Soon the gang begin to individually design a new treehouse and they introduce the ideas to Frank at the Sugar Bowl, but in the end the gang decided that instead of a different design the original one was much better. So the treehouse is rebuilt the way it was before and Frank leaves, giving them a picture of a building he designed and only then does everyone realize who he really is.

Trivia

 * Buster references his first dinner with Harry from Bitzi's Beau.
 * The name Frances appears in this episode. It's unclear who Frances is, but Frances would be joined by a list of ten other unidentified student's names in the Season 13 episode, Arthur's Number Nightmare.