The children of light left the humans and traveled west over the frozen lake. They reached the edge of the cavern and spied a ledge above them, and after climbing up to it they discovered the opening to a hallway of stone. This passageway narrowed as it sloped upward, and the party followed the tunnel until they emerged into the cave they had first entered after landing on this mote of earth. The heroes decided to explore the spiral staircase to the north. As they descended, they noticed dark striations in the ice around them, pulsing with light-consuming, necrotic energy that reached from the dimness below. Neri lost her footing near the bottom of the slippery steps and slid to the floor below before slamming into a double door of black iron, a single eye worked into its face. The unholy energies the heroes had noticed on the staircase seemed to emanate from beyond the ominous door, and those with keen ears could hear wailing through the heavy iron. Neri said that the voice belonged to her brother, Aten. Ember summoned sacred flame and flung it at the barrier. A small part of the black door melted, but arcane wards reacted with a blast of necrotic energy that smashed into the cleric. The group examined the door and surrounding area for several minutes before realizing they would never be able to get through this entrance without more knowledge or an arcane key of some kind. Hoping that they might find what the needed in the only part of the cavern complex they had not yet explored, they climbed the stairs and made their way to the hall where the chimera and arcane traps waited.
Alec entered the large room first, treading carefully into the fog hovering near the ground. He had taken only a few steps when tendril of mist extended and wrapped around his leg, its touch leaving numb wounds and dazing the warlock. Glace teleported to Alec's side, and the two made their way carefully to the runes on the west wall. The warlock examined the runes and realized the magical traps were scattered about the room; in order to disarm the floor-traps he would need to find and deal with each one separately. Demarung and Glace, the two children of light with the keenest senses, began slowly moving about the room, finding rune-traps as well as pressure-sensitive floor stones near the portcullis. The rest of the group began to move into the hall, carefully avoiding the arcane traps, when the door behind the portcullis opened and an undead figure emerged, clothed in a raggedly stitched robe and wearing an amulet in the shape of a single, baleful eye.
The follower of Vecna immediately attacked, casting a spell at Glace and pressing a panel on the wall that raised the portcullis. The chimera, now freed, breathed a cone of frost over Glace and Alec as the warlock leveled a curse at the great beast and the robed figure. Demarung hurled his enchanted javelin at the chimera, wounding it as Glace teleported to its flank. The avenger struck with his flail, hurtling the monster to the middle of the room where several arcane traps fired, adding to the beast's injuries. Neri leapt over a trap on the floor to engage the chimera as well, striking first with her acidic breath before slicing the monster with her sword and goading it forward into yet more traps. Ember attempted to follow the dragonborn into battle, but stumbled as she stepped over a rune on the floor; a misty tendril attacked the dwarf, momentarily dazing her. Aria began a battle chant to bolster here allies' attacks, then used her arcane power to heal Glace's wounds. The robed figure avoided direct combat, instead casting a necrotic spell from the far end of the room. The unholy magic burst among the children of light; Demarung, Alec, Ember, and Aria felt the power of Vecna as his priest's spell inflicted deathly wounds. Alec reacted with a dark spiral, momentarily surrounding his foe with a black cloud that assailed the undead cleric's mind. The chimera attacked next in a frenzy, each of its three heads laying about it with tooth and horn. Glace dodged a bite from the dragon head only to feel the lion head's jaws strike true, while Neri blocked a goring attack from the goat head's horns but suffered a wound from the dragon's teeth. Ember, still dazed by the arcane trap, first bore a savage mauling from the lion head before being gored by the goat horns. The dwarf fell, and Alec rushed forward to pull her to safety as Neri and Glace swung at the chimera to distract it. The warlock administered a healing potion to Ember, then stood and cast a curse grind at his two foes, slaying the undead cleric. Demarung swung his sword at the chimera, slicing into its tough hide as spectral thorns sprouted from his weapon and pulled the beast forward. Two more arcane traps fired, further injuring the monster while Glace shifted to the beast's rear flank and launched a flurry of strikes, landing three blows with his chilling flail. Badly wounded, the enraged chimera spewed another cloud of frost at the children of light in front of it. Glace struck again as Demarung and Alec dodged the monster's icy blast. Aria and Ember were less lucky and felt the full force of the chilling cloud. The dwarf lashed out at the beast with a wave of Astral energy while Neri slashed at the chimera's flank and Aria sang a savior's song to help her allies shrug off the effects of the icy blasts. The monster attacked again, each of its heads targeting a different hero. Neri blocked the dragon's maw with her shield, but the lion head's jaws savaged Demarung and the ram head battered Alec, knocking him down. Neri saw the chimera's attention focused on her allies and sliced into the beast's side again with a mighty blow as Alec rose from the ground. The warlock leveled a final curse at the monster, assaulting the creature's minds with arcane power and killing it.
As the children of light carefully moved around the chimera's corpse, Alec attempted to disarm the pressure-plate trap near the portcullis. He triggered it instead, and the two ice statues standing nearest him raised their arms and blasted the warlock with rays of cold. Glace leapt beyond the trap; beyond the door he discovered a small library. As the avenger searched the books, the rest of the party made their way around the runes scattered around the room as Alec attempted to disarm one of the arcane traps. After several unsuccessful attempts resulting in attacks by the mist-tendrils, some palliative healing spells from the cleric, and a few leaps, the entire party made their way to the library as well. Many of the books were arcane tomes, including a treatise on rituals and three volumes on necrotic magic. Another described arcane doors, portals, and wards, and Alec felt sure that studying this book would enable him to open the door at the bottom of the spiral staircase. Further searches in the library revealed a secret compartment containing residuum, and a journal written by Ven Knadal, the human who named himself Vecna after becoming a lich. The diary described Ven's contact with agents of Erek-hus and the process by which the human had become undead – and hoped to become a god. Vecna wrote extensively of the being Erek-hus, noting that he seemed to be undergoing a transformation from his original elemental, destructive nature into something new. The lich's notes revealed that he believed Erek-hus had begun to heed the words of the God of Chaos, at the bottom of the Abyss. The final pages of the journal featured a sketch matching the drawings found on the walls in the lair of the Spirit Talker. According to Vecna's writings, both the stone hand and the clawed, demonic hand represented Erek-hus, and symbolized his transformation from primordial into something more alien and sinister.