After a few minutes of resting, Karyn realized a couple of things. First, she realized that she was being affected by at least some of the things she'd written down with the pencil for Sarah. And second, she didn't know whether or not Jon had said anything to Sarah about the stone and/or the pencil.
"Jon," she asked, "Where's the stone?"
He pointed over to his desk. When she looked again, she was happy to see that it was there. She got out of bed to get it. Once she was up, she realized that the pencil was next to it. Now to see if we can get rid of some of those, she thought.
She picked up the rock, and said, "I wish that the paper on which I wrote wishes yesterday were in my hand."
It appeared there immediately, but it was grease and other, less pleasant, things. Thinking quickly, she said, "I wish this paper that I'm holding were completely clean."
"Did it work?" Jon asked, from the bed.
"No," she replied. "It removed all the writing as well. I guess that rules out erasing the writing. Maybe I can write something reversing it..."