Pencil scratched on paper.
The following, Jon wrote, are the conditions binding the wish granted by the stone in reference to this paper, until another wish on the stone is made to reverse the aforementioned wish and re-merge the resulting distinct identities of the former Sarah McMillan. The listed conditions will reverse also, in that event.
Jon stopped, read back what he wrote to check for spelling errors, and pondered. The stone sat safely away from him, on the corner of his desk, where there wouldn't be any accidental wishes as he worked. He wouldn't need it until his wish was ready, after all, and not trusting himself to get such a long and complicated wish out in a single breath, he'd need to write in all out on a bit of reference paper before actually using the stone.
Sarah McMillan, he continued to write, is henceforth to be split into two identities, each with their own name, body, personality, and life, derived from their previous identity as Sarah in the manner set forth below. One of these identities will be named Clara McMillan; the other, Saraiah McMillan.
For what might as well have been the hundredth time that night, Jon found he was second-guessing himself. Making a wish to "fix" Sarah in some way had occurred to him naturally enough after he left Karyn that morning; it wasn't really her fault Karyn ended up the way she did, but then, Sarah was closely related enough that she stuck out in Jon's mind anyway, enough to get him thinking. There was no denying how cathartic the thought of Sarah getting a nice, hard, magical slap of karma to the face felt to Jon, but on the other hand, if his ultimate goal was really the nobler idea of making Sarah into a better, nicer person, why bother with the middle steps when he had the stone?
Clara McMillan is to embody all of Sarah's best qualities, and will be more likeable, morally upright, and generally regarded as a much better person than Sarah was. She will be more popular than the former Sarah, and form much deeper and more genuine friendships with those about her, being vastly more likely to genuinely sympathize, as well as being generally more visually attractive. She is to be kinder, more compassionate, more fulfilled, and generally much happier than Sarah was.
Part of Jon was tempted to make the dream girl Clara his girlfriend or something, but he figured that could always come later as long as he had the stone. Besides, Karyn would be pissed, and justice could be a very punitive mistress, as Saraiah was most likely about to find out. If she didn't, well, that's why Jon still had the stone.
Saraiah McMillan is to embody all of Sarah's worst qualities, and will be far less likeable, morally bankrupt, and generally regarded as an even worse person than Sarah was. She will be a social outcast, with almost none to truly call her friends, being more purely an antipathist than Sarah, as well as being vastly less visually attractive. She is to be crueler, more callous, more unfulfilled, and generally much more miserable than Sarah was.
Another part of Jon really wondered whether it was the right thing to be bringing someone like Saraiah into the world, just as retribution against her former identity as Sarah. Maybe it wasn't, but still, revenge could be sweet, and after all he was explicitly wording his wish so that it could be undone later, if all went wrong. And even besides that, he was letting Karyn know about the wish, just as a second pair of eyes, so it wasn't all up to his sole judgment anyway.
Saraiah and Clara are to recall all of Sarah's memories from before the split like their own, as though Sarah was in earshot of the wish despite not hearing it. So too are the memories of Karyn Black to be unaffected, as are my own; and the memories of anyone we later wish on the stone to restore, will be restored. The remainder of the affected world is to recall Saraiah and Clara as twin sisters from birth.
And that was about all the essential stuff, Jon thought, save for the details so important he wanted them spoken aloud when he was making the wish. He wrote these down, too, but on another part of the paper he reserved for drafting the actual wording of the spoken wish. When he was satisfied, he took a deep breath, then another, then the stone, and then the paper, and finally sealed the deal.
"I wish that until someone wishes on the stone that they would merge back together as the original Sarah, Sarah McMillan would split into two distinct identities as described on the paper I'm currently holding."
The stone flashed, and across town, Sarah suddenly came down with a throbbing, skull-splitting headache.
