Holding the stone, Jon said "I wish I was a genius." The stone glowed, indicating that the wish had been granted, but Jon really didn't feel any smarter. He thought that knowledge and ideas would fill up in his mind, but none of that happened. At first he thought that the stone didn't grant his wish, but then he looked up.
Jon's house was gone. In fact, everything Jon knew was gone. He was standing in the middle of a forest. Looking down, Jon was shocked to see that he was wearing nothing but a loincloth made out of some sort of animal skin. "Oh my God!" Jon said as he realized what he had done. "I've made every human in history stupid. The human race must be like cave people!"
