Jon ran out to the street, then stopped. He had to figure out where Karyn would have gone to. Since she thought that she was Zoe, maybe she went to one of the houses of Zoe's friends. Or maybe she went to that Goth club, or maybe that occult store. He grabbed his head, not knowing where to go. There were just too many places to check and he didn't know where all of Zoe's friends lived.
Suddenly, his cellphone rang. He took it out of his pocket, thinking that it was the unknown caller again. But the ID said KARYN. That was the fake Karyn, the one that was part of this demented game.
He didn't answer it and just let it ring and ring. He felt a little bad about not answering. Sure, the girl wasn't Karyn. But she thought she was Karyn. And obviously she was worried about him.
Jon wondered if he should rethink things and answer the phone. Maybe if he figured out who this girl was, he could at least get her back to normal. He still wanted to fix Karyn first, but he didn't know where she was and he'd probably have a better chance with this other girl instead.