Editing Skein of Worlds:Cosmology and Setting (section)

=== The Deep Places ===
It has already been mentioned that you can travel deeper and deeper into the Ethereal Planes, but the same is also true of the other transitive planes. On the Astral Plane, if you attempt to travel towards the gray horizon in between the three great orbs, they will eventually fade into the distance and you will be surrounded by an endless gray nothingness. This is the beginning of the Deep Astral. It is possible to get farther and farther away from everything else in the cosmos, but little is known about what, if anything, is out there.