How is the dark unknown if you can define it as the dark? It is the light that is undefinable. Because even when you see you can never be sure of what it is that you are seeing. Faces are masks where your eyes are the only slits that allow a glimpse of the soul. Everyone has a slave in a shadow, it does what you do, when you do it. But as soon as it gets dark, the shadow gets a chance to escape and be free in whatever realm it is that shadows are free.