When the group returned to the water-filled passages, they elected to explore only at full strength. To accomplish this, they rested for almost two full days to return to full health and with a full repertoire of spells.
It was decided that Barrett and Karn would go ahead, they being the best swimmers. They stripped down to undergarments and gingerly waded into the cold water. Taking Vald's glowing lantern with them, they dove into the inky depths. They swam for what seemed like hours to their tortured lungs, but was but moments in reality. Following a wall, the circumvented a large room and came to a door partially open. Barrett made to return to the others, but Karn swam through the opening. Reluctantly, Barrett followed. Luck was with them, as a set of steps rose out of the water on the other side of the door.
Freezing in the air, they soon saw that the stairs led only to a landing with a familiar iron door. Broad and without any handle or hinge visible, it nonetheless had three iron skulls above it, two with glowing eyes. Barrett advocated returning to gather the others before opening the door, but Karn argued the others – the dwarves in particular – would not survive the swim. When Barrett turned his back, Karn slapped the now-familiar button beside the skulls. The third skull lit up, but nothing else happened. Karn was about to push the door open, but Barrett managed to convince him that they should do so only with the others. Another long, cold swim later, they emerged to the relieved faces of their companions. It was decided that the first door they discovered would be the one they opened, and the group set out.
Soon, they were at the door and ready. They carefully advanced, to find a bizarre sight. In an immense dome, an unsettling glow from a large skull-shaped stone in the wall illuminated many piles of earth, a broken orary, and one of Vald's kinsmen. It stood lean and dangerous looking, a single sword sheathed at its' hip. In badly accented common, it invited them in to experience the glory of the Nightstone. Karn approached the farthest, with other lurking near the entrance or flanking to the sides. The creature that identified itself as Caullum showed no sign of fear, and conversed with them, offering to allow them to touch the Nightstone. Only Karn dared, and he felt an unearthly chill when he did. Finally, the group approached as Caullum drew his sword. It seemed to be covered in ice, a mist wafting from it in the air.
The battle that followed was fierce. Caullum was no novice swordsman, and the heroes were hard-pressed. He slashed them and confounded them by transforming into a huge spider that ran up the dome. They were soon caught in a web. The skull meanwhile, flashed red often – and they soon realized that it was healing Caullum. The group soon escaped the web, and the battle continued. Many were laid low, but eventually Caullum was killed. The heroes had his corpse looted in short order. While exploring the chamber, they ignored Caullum's body. They soon regretted this, as the skull continued to heal him! He rose up and fought them again. Since Karn had taken his enchanted sword, his attacks were less successful and he was soon brought down again. This time, the group remembered Pyorrhea's words and used the dirt mounds to bury the skull. While doing so, they uncovered wealth and weapons! They barely had time to revive downed party members before a noise at the door alerted them. Vald's kinsmen returned, including the queen. They thanked the party for their service, but soon began salivating and commenting on how tasty the heroes looked.
At Vald's shouted insistence, they fled. Running like the hounds of hell were behind them, they fled through the hallways and up the spiral stairs. Continuing to run, they couldn't miss the fact that a large number of the creatures were following. Out of breath, they reached the bottom of the great stairway leading to the surface. Even Vald was showing signs of wanting to leap upon the heroes. Instead, he took Dankhan's warhammer and started smashing the side walls of the stairs, shouting for the others to flee. Heartbroken, they took his advice and rushed up to the surface as the walls behind them collapsed. Dust and debris followed them out of the hole, letting them know how close a call it was.