Cleon and Aaron have fought their way out of the sewer passages and into another massive underground cavern, dominated by a enormous lake. They have been betrayed by Kurzak the Blacksmith, and he has left the party to own devices following an argument with Cleon. After careful watching of the waters, as well as testing the flammability of various items, they have discovered that the lake is producing a large amount of methane, and that the ceiling of the cavern is likely awash with it. The lake itself contains only murky, polluted waters, with strange creatures only glimpsed beneath its surface. After resting for a short while, they press on, searching the cavern for a way out. They discover a path of large boulders leading out into the lake, and coming a large, octagonal island. They defeat the daemonic guards, they gain entrance to the building that dominates the island.