Buster found a note in his pocket reading:
We'll find room
The desert today."
After the kids realized that things seemed to keep appearing in Buster's pocket, Buster realized that the note was actually old. They had thought that "C.E." referred to the Coin of Excellence and that they were supposed to search for clues in a simulated desert. The note was actually from Arthur, passed during a hot day in class. "C.E." referred to chocolate éclairs and Arthur was telling Buster to find room for "dessert," which he had misspelled.