The Farther is every cavern, gallery, cave, tunnel, hole or nook that exists so far out from the Stairway that it isn’t even in the poorly mapped regions of the Reach. If the Reach is the Wild West of Infra, the Farther represents the no man’s land.
Things live in the Farther that no body would want to know about or contend with — not even those fool-hardy enough to live in the bordering Reach. If there are demons or twisted men who live deep in the bowels of the World, they live in the Farther, clawing at the edges of the light from the Reach and the Atria, hungrily waiting for some fool-hardy adventurers to go thinking they can strike it rich out in the unmapped halls of the World-Beneath-the-World.
There are those mad men and women, those who talk and talk and never truly listened to or are disregarded as fools and blowhards, who swear that the Farther holds the remnants of civilizations never before seen or that all the glory of Infra lies within the depths of the Farther, waiting for the right man or woman to pick it up…and still more who say that the Haruspices exist here, somewhere far from anyone they can harm.