"Well... it's a long story," said Karyn. "But not such a long story that I can't explain it. Me as Karl, and Sarah, were out in the woods getting lost, when we found this old shack in this clearing. Or, rather, we didn't. We kept saying we were going to see what was in it, and a second later we forgot what we were going to do."
"Huh?" said Jon.
"I told you it's a long story. Finally we figured out something was funny and we kept in contact by cell phone. I watched her from the edge of the clearing and every time she turned around I called her up and reminded her to go into the shack. As soon as she reached it and opened the door the spell was broken. We found a dried out old man's body--he was dead for decades--and a bunch of magic items. We must have been the first people to ever get past the spell making everyone ignore the shack."
Jon asked, "I don't suppose one of those items was a Necklace of Truth?"
"Yes, one was the same necklace you're wearing. How did you get that, anyway?"
"I wished for all the magic items in the world."
"The stone has a range limit," said Karyn. "You probably got all the magic items in range, not in the world. I bet you just got everything that was in that shack. Anyway, we played with the items. I took a wishing stone. Sarah tried a few other things."
"But it's my wishing stone!"
"That's what you remember," said Karyn. "Now, one of the items Sarah used was a magic cabinet. The inscription said it lets someone be in two places at once. That seemed harmless enough. It had one door on one side and two doors on the other. Sarah opened the one door, walked in, and out walked two of her. We thought it was great, I thought having two girlfriends was fun... until later that day. One of the Sarahs decided she didn't want another one of her around and told the second one to stay out of her house."
"But if they're both the same person, they both have an equal right to...."
"I know. The second Sarah came over to my place and I made a wish to know why the first one was acting like that. It turns out the cabinet doesn't make two of the same person, it really makes a good and an evil twin. At that point I started really using the stone."
"I think I see where this is going..."
"My first wish was to destroy the cabinet. My second wish was that we never found the magic items, except the stone. And my third wish was that we were hidden from the evil Sarah. But I made a mistake and did it when you weren't paying attention. So you never heard it."
Jon waited for Karyn to continue, but she didn't.
"That's it," said Karyn. "We're about as hidden as we can get. Good Sarah became you, Karl became me, you got the stone, and evil Sarah is just evil Sarah."
"What was, er, the original Sarah, like?"
"Somewhat between you and evil Sarah, except that you're a guy."
"Uh, and what does evil Sarah remember?"
"I'm not sure. If we never found the magic items, she shouldn't remember anything, but then if we never found them, she shouldn't exist. But she does. So who knows... maybe the stone can't completely reverse another magic item's effect?"
"When did all this happen, Karyn?"
"Yesterday. I just got back from visiting relatives, remember?"
"Yesterday?"
"Yeah, you didn't get the stone from your grandfather, you just remember that. He isn't even your grandfather, and he might not even be dead. You never turned the tree branch blue and I never wished for blonde hair and boobs. Reality just changed so it seems like that."
Jon didn't recall Karyn using the word "boobs" to refer to her breasts. Of course, if she was really Karl, maybe the memories were false, and she did talk like that.
"I was up late last night trying to figure out what to tell you and what to do. I'd have to explain everything, which would be hard on you, or else lie, borrow your stone, and reverse the wish without ever telling you."
"You figured out how to reverse it, right?"
"Yeah, I can wish we were hidden because evil Sarah forgot where my house was or something like that. But if I do that where you can hear me, you'll be good Sarah, yet still remember being Jon. What do you think we should do?"
EDIT: Karyn does, of course, use the word "boobs". Please assume she said something else that she doesn't normally use.
I'm not posting a whole fixed chapter just for this.
