[A blank space, accessible only by people from other worlds, anchored by an object of this world. A plane of conjuration. There's a lot to peel back, there.]

All right. When one enters this Horizon, you step out of this world? Through what means? [She sees it in her minds eye, a great rent in the catacombs' wall, searing violent and green and blue at its scintillating edges, a hellish landscape speeding past on the other side. Could the Singularity be an entrance to the Infinite Corridor? A method of navigating it, even?] And if you have a keep there, then--ah! I knew you weren't actually living in a cactus!