"I wish that Jon would immediately find a useless replica of the wishing stone in his bedroom, that looks exactly like this stone and glows like this one does except that when it flashes it cannot grant wishes."
Sarah smiled as she watched Jon lcoate the fake stone she just planted in hsi room.
"That should keep Jon off my trail," Sarah said smugly to herself. "What's more, I'll be watching him. If Jon tries to make a wish with that fake rock, I can always choose to grant it for him using the real one - but only if, and how, I want to of course!"