That night, Jon was fiddling with the stone. Nothing major, until happened to ask the stone about if any wishes affected him... the answer was a little strange. He immediately called up Karyn, who came over right away.
"So what's so important?" asked Karyn. "You said something about having changed the past. Wishes usually do that anyway, right?"
"Well, they do," replied Jon, but that's not what I meant. I meant I really changed the past. Or rather, I'm going to change the past, but it already happened."
"I still don't get it," said Karyn.
"Think of it this way," said Jon. "Imagine I have blue skin."
"But you don't."
"I know, but imagine it. I'm standing here with blue skin. I've always had blue skin, or almost always. It's been a part of my life, it seems perfectly normal because I've always been that way, even if someone who meets me could think it's strange. Well, the whole reason I have blue skin is that tonight I'm going to say 'I wish I was born with blue skin, sixteen years ago' or 'I wish my skin turned blue ten years ago'. My wish affected the past. I haven't made the wish yet, I'm going to make it soon, but since it affected the past--for real--we've already seen the effects. And I'm going to have to make the wish just to keep things the same as they are now."
"So any strange thing I know about you now could be caused by the wish about the past, even though you'll make the wish later."
"Could be."
"Hmm. Jon, what if it affected the present and the past?
"What do you mean, Karyn?"
"Suppose that tonight you say 'I wish I would time travel into the past and end up becoming my own grandfather.' Well, your grandfather's always been part of your past, so you have to make the wish just to stay as you are. But it also means that you're going to disappear tonight into the past and I won't see you again unless after becoming your grandfather you wish yourself back here again. In fact, it's a wish. You could become your own grand mother. You could have started as a baby or an adult, or keep your memories or not."
"Maybe," said Jon, "all my life my grandmother told me stories of how she used to be me but she made a wish. And I didn't think of it as any more than bedtime stories until I got the stone and knew that it's true."
"Well, did she?" asked Karyn.
"No."
"Then I don't think I can guess it," said Karyn. "There are just too many possibilities. Maybe your wish will have created something strange in the past that I already know about. Maybe something I don't know about. Maybe something that wouldn't look strange at all--if you became your grandmother you'd look like a normal grandmother, I would have no way to tell. Maybe it's not about you at all... maybe you wished that your brother's skin turned blue when he was five, or that he started liking spinach back then."
"My brother's skin isn't blue and he doesn't like spinach."
"Those were examples. Come on, Jon, you say you'll have to wish for something, but it happened in the past. What is it?"
"Okay, well this is what it is...."
