In the darkness of the underpassages, lives a people, not unlike the humankind that walk earth, but not altogether similar. The skin is dark as well as the eyes and the bones of the teeth. They choose if they wish to be seen. That is, the females choose. The males emit a soft bluish glow that they've never learned to extinguish, if indeed they are physiologically capable. Given the widespread inability of the males, it's logical to assume they are disabled in this regard.
These people, to use familiar terminology, live alone, although some temporarily collect in small tribal formations scattered through a vast network of tunnels carved into the earth crust. When I first encountered them, I wondered why so many of them chose to live alone. It seems natural that humanoids should congregate in groups that continuously grow over the passage of time. Yet, despite evidence suggesting these creatures have existed for thousands of years, still they have not progressed. I would later come to understand why, and what I learned in my misadventure would challenge everything I thought I knew about what it means to be human.
