This was his last chance. Jon had to get that stone back.
While Biff thought about what to say, Jon lurched forward and tried to grab the stone, but he failed. Biff knocked him back down onto the floor.
He looked back up at him and saw him mouth the words "I wish" and then followed them with more words. But Jon couldn't hear them. All he could do was watch Biff's mouth move.
Dread washed over Jon as he knew that he only had a few more seconds of being himself. After the stone glowed, he wouldn't remember any of this. He wouldn't be Jon anymore. At least, not the Jon he was right now.
He closed his eyes, not wanting to watch the stone glow, not wanting to know that that was it.
A few seconds later, Biff said "It's done."
