Biff backed out of Sarah's arms. "You know? Then why are you so okay with it?" he asked. She was wearing clothing that he should have been wearing. If she knew she was being affected, then why didn't she try to make herself look more like herself?
"I'm not okay with it," she said. "I'm not sure what's happening, but I know I can fix it. I've been doing it all afternoon. With one touch, I can make people normal again."
Biff looked down at himself. "Well, you just touched me. How come I'm not normal again?"
Sarah looked confused. "But you're already normal, babe."
Then it clicked. Sarah was seeing people who hadn't changed and thinking that they were backwards ... and then going out of her way to change them! No, this was horrible! Not only was Biff unwittingly changing people, but his girlfriend was doing the same thing, only on purpose?! He had to stop her!
