Deep in my memories, I had not noticed our path, but now the dark forms of my guides paused beside a gap in the stone flagging, where a stairway which I had never seen during my wanderings about the castle led into subterranean depths. Down this stairway I was conducted, and presently I came to realize that there was light of a sort—a dim, phosphorescent radiance that came from no recognizable source, and seemed to be less actual light than the accustoming of my eyes to the near-darkness.