"Jon? What are you doing in my room?" asked the teenage boy. It took Jon a few seconds to realize that this was Mikey. His voice was deeper and he looked like he might need a shave in another day or so, but it was definitely him.
"I ... uh ..." Jon began, trying to think of an excuse. And that was when he noticed what was in Mikey's hand. It was the stone! Suddenly, Jon realized what must have happened. In this new reality, his grandfather must have sent the stone to Mikey instead, because he was the oldest.
If he could just get his hands on the stone, he could reverse all of this. But he had a feeling that it would be more difficult than just snatching it from his brother. Mikey was a lot bigger now, and Jon was a lot smaller.