Sex Change Operation: Karyn Doesn't Remember

"Karyn, listen," Jon said. "Yeah?" He looked around, making sure they were alone, which caused Karyn to look at him funny. "What? What's wrong?" "I made a wish last night and now everyone thinks I'm a girl who had a sex change. You know how the stone works. Since you didn't hear the wish, your memories ..." "Jane ... sorry ... I mean Jon," she said. Then she muttered to herself "I don't know if I'll ever get used to that name." Then she asked him "What are you talking about? What stone?" Jon stared at her. Could it be that his wish changed reality so much that Karyn had forgotten about the wishing stone? Did he even *have* the wishing stone in this new reality?