Unfortunately for Sandy, and very fortunately for Joan, there are certain kinds of wishes that aren't good.
Most of those were obvious--wishing for breasts that can't be reversed, wishing to be younger without saying how much, and that kind of thing. But there was another kind of bad wish that neither Sandy nor Joan knew anything about:
Making wishes about the previous owner of the stone.
The stone changes reality. If you wish the previous owner of the stone was somewhere else, then reality changes so that he really had gone somewhere else. And if he went somewhere else, he would have taken the stone with him.
Sandy changed reality so that Joan was a pregnant girl in a hospital. Then Joan went to the hospital instead of school. Then Joan lost the stone at the hospital instead of at school.
Sandy suddenly noticed she was no longer holding the stone. What in the world had happened? She didn't even know her wish had really come true, but it was like it had vanished... what? Suddenly she realized there was a light being shined on her. She looked around. She was on the stage in a costume and people seemed to be expecting her to say her lines....
Joan's mother picked up the stone. "Joan, you dropped this," she said. "I'll keep it safe until you're okay."
"Wait!" yelled Joan. "I need that stone now!"
