The Furthest Ring is an infinite space that exists outside of all universes. It physically borders the outside of every Incipisphere, containing the orbit of Derse and separated from The Medium by The Veil. the ring is home to a number of eldritch monstrosities, including Fluthlu, Nrub'yiglith, and Oglogoth. The most powerful of these monsters are the Noble Circle of Horrorterrors. Dersite Dreamers are able to see and hear the Horrorterrors by staring into the space beyond Derse.
Temporal and spatial factors are far less than constant in the Furthest Ring, due to it existing beyond any universe and therefore never having the spacetime principles solidified; the deeper into the Ring one would get from their session, the less stable time is, and as one spends more and more time in its dark reaches, space becomes less reliable as well.