There was a flash and when Jon looked back the rock was gone. In its place was a plain-looking keycard.
Jon held it in his hand and tested it. "I wish that my hair would be blonde for the next ten seconds." The keycard glowed, just like the rock, and Jon saw that his hair changed to blonde. And after ten seconds, Jon's hair changed back to its normal brown color.
He put the card in his wallet and left his house to go visit Karyn.