Karyn sat in her room holding the stone. Sooner or later, she and Jon would have to find out what had happened to the original stone. In the meantime all they had were the twin stones--whenever one person made a wish, both would get it.
It was a pity, though. Once they did that Karyn wouldn't have a magic stone any more. Oh, Jon would probably lend her the stone, but if she really wanted unlimited use it would have to be now.
Permanent wishes were risky, though. But she wondered, maybe just one silly frivolous use. Could she pull a prank on Jon? It was simple. It just took two steps.
"I wish the next wish can be reversed" was the first step, just for safety.
The second step was just to wish for something that wouldn't be an inconvenience to herself, but that would be amusing on Jon. If she wished to wear a dress, she and Jon would both be in dresses... but it would be a much bigger change on Jon than on her (not that he'd remember it). What could she do? Hmm... "I wish..."