What's the Difference?

Timmy's reading a find-it book when Mark Chang, in his traditional alien form, shows up. His changer is broken, and without it, Mandie will find him. In a last ditch effort to save Mark, Timmy wishes the school was like his book. But she is about to turn the school into a crater if Mark doesn’t show himself. If Cosmo and Wanda had their wands, Timmy could just wish her away. But where are the wands hiding?