Sarah is Karyn's roommate--and not because of a bad wish

"Only my roommate. She's Sarah McMillan. She's gotten a little nicer since you last had the stone but I still think we're in for trouble. I hope we can tolerate each other." "Let me help," said Jon. "I wish that Sarah won't steal any of Karyn's stuff, or play any pranks on her." "Maybe you should just wish that I'm not Sarah's roommate." "I don't know, Karyn. We'd have to be very careful how we word it. If you turned into a cheeseburger, you wouldn't be Sarah's roommate." Karyn laughed. "Jon, you sound hungry. And I'm hungry too. You know, if things are as if we drove to campus, unpacked, and walked around looking for each other we would be a little hungry. Why don't we get something to eat? The meal service isn't open until tomorrow, but there's a Burger King across the street." "Or I could wish for better food," said Jon. "It's been so long since I've had the stone, and I never really got a chance to use it much." In the end, they decided to go to Burger King. After they finished eating, Jon lent Karyn the stone in case she had any trouble with Sarah. When Karyn got to her dorm (or, as everyone else remembered, got **back** to it), she sat down on her bed and shuffled through some papers, looking over the map of the campus and her course schedule. She also put the stone down beside her--and neither she nor Jon had realized that Jon's wish only kept Sarah from taking **her** stuff, but the stone was Jon's, not hers. And when Sarah entered the room....