The solid rock now gave place to the giant foundations of the monstrous castle, and it seemed that the speed of the party was somewhat abated. Vast walls shot up, and there was a glimpse of a great gate through which the voyagers were swept. All was night in the titan courtyard, and then came the deeper blackness of inmost things as a huge arched portal engulfed the column. Vortices of cold wind surged dankly through sightless labyrinths of onyx, and Carter could never tell what Cyclopean stairs and corridors lay silent along the route of his endless aerial twisting. Always upward led the terrible plunge in darkness, and never a sound, touch or glimpse broke the dense pall of mystery. Large as the army of ghouls and night-gaunts was, it was lost in the prodigious voids of that more than earthly castle. And when at last there suddenly dawned around him the lurid light of that single tower room whose lofty window had served as a beacon, it took Carter long to discern the far walls and high, distant ceiling, and to realize that he was indeed not again in the boundless air outside.