Conversation so far:
what is the main idea of the movie up?
In Up, Carl sets to fulfill his dream to see the wilds of South America, a promise made to his late wife, by tying thousands of balloons to his house.
who wrote the story for the movie Up?
Bob Peterson, Pete Docter, Tom McCarthy

Question: what was the story based on?
Self-contained rewrite: what was the story for the movie Up based on?