Then suddenly, without any warning, the tunnel ended, and the two mares found themselves in a huge stone cavern. It was filled with empty space, a curtain of dust hanging in the air like a smog, shifting and shimmering under the light of the fires burning along the walls. Twilight looked at the massive stone pillars and the boulders lying around and shivered as she remembered the levels within Tartarus she had seen only minutes ago. A small waterfall of lava flowed into a small pool up against the far right hoof side, bubbling gently.