birdfang quoted Vertical motion by Canxue
Even though people never descended to our underground, we actually gained all kinds of information about the mortals above us. I don’t know what sort of channel this information came from. It is said that it was very mysterious, and that it had something to do with our builds. I’m an average-sized, ordinary individual of my genus. Like everyone else, I dig the earth every day and excrete.
— Vertical motion by Canxue