Sarah really tried to stop walking. But her feet wouldn't listen to her brain. They kept on moving ... until she got home. Then she had control over her feet again.
She turned and walked back to Jon's house. She knew that she couldn't get the stone back and that she couldn't harm Jon or Karyn, but there were ways to get around that. (Like using a bat or something to beat Jon down. Technically, it wouldn't be Sarah who was harming Jon, it would be the bat.) And, if she made sure that she didn't get noticed, then maybe just maybe she would be able to execute her plan and seek revenge on the people that did this to her.
