Jon figured that the stone caused him to repossess the body of Sierra, but he wasn't sure why.
He walked back to his bed, thinking that the stone would be there, since that's where he woke up. But it wasn't. He looked all over his room, but still couldn't find it.
Could it still be at David's house? Jon didn't even know where David's house was, or if it even existed anymore. Was the stone gone forever? Jon hoped not. He didn't want to spend the rest of his life as Sierra.