The wish Jon made was "I wish that any wish made from now on will only last for an hour, unless otherwise stated."
The stone glowed.
"Hey! What's that?" asked Zoe, Jon's 14-year old Goth sister. She ran through Jon's open bedroom door and snatched the stone from him.
"Zoe, give that back. You don't even know what it is."
"Sure I do. It's a wishing stone," she said.
"How could you know that?" Jon asked.
"Jon, I know a lot about the occult. Remember?" She turned to leave.
"Wait a minute. Give it back to me," Jon said.
"No way. It'll be better off in my hands." Then she ran out the door.
And Jon chased after her, hoping to stop her before she made a wish.