Sarah was now Jon's best friend, like Karyn had been in the old reality. And in this new reality, Sarah was nice and caring, the way Karyn had been previously. What have I done? thought Karyn. Now that she was Sarah and Sarah was her, Karyn would have to find a way to reverse this and get her best friend back. Karyn reached for her stone, only to find it was no longer there. She realized that if she wasn't Jon's best friend, then Jon wouldn't have showed her the stone to begin with. And not having access to the stone made it so she couldn't have wished for one for herself. She had to find out a way to get the stone from Jon or Sarah, whichever one currently had it.
Meanwhile Jon and Sarah.....