Another gamble begins. It seems that all the stones in the village are empty. Even though they've worked in the mines for years, they're still not sure of the source of the stones. They've gambled all their money on them, and now they'll all be ruined. They can't figure out how to dig up the source, and they'd better hurry back to the mines. They just filled the stones with more stones, and sealed the source with magic. This is why the stones are empty: they were already cut open. They took away the source inside, filled it with stones, sealed it, and then filled more stones with it. They won't admit it now, but it's going to be a big problem in the future. So they should just go back to where they came from and bet.