The Wishing Stone

While hiking in the woods around Spooksville, Adam and his friends find a cube-shaped stone. It is clear, like a crystal, and seems to shine with colored light. To their immense surprise, the discover that if they hodl it and make a wish for something, that thing happens. They call it the Wishing Store. And they love it.
Until they discover that there is a heavy price to be paid for each wish.