Now accompanied by Stahlstrauss and Eshunu, Zil'dejin and Lythanis proceed with Valthrun further into the dungeon. They are met with a fork in their path; on one side, a small passageway leading to a corner, and in front of them, a large set of iron-bound double doors. Thinking it best to eliminate their less imposing options first, they proceed down the small hallway.
The hall ends with a door that has been barred by a single board nailed across it. Scrawled roughly on the board in common script is the word "Closed." Knowing better than to heed such warnings (or perhaps just not caring), Zil'dejin smashes the board and opens the door. The party proceeds, with Valthrun preferring to stay where the light is.
Inside, the room is pitch dark. Lythanis lights a Sunrod, and the room becomes clear enough to see; it is immaculately clean, and he is able to notice a very thin silvery trail on the floor, not entirely unlike that made by a slug. However, nothing else appears to be inside. Stahlstrauss tentatively goes to investigate the end of the trail, which appears to be in a small alcove further down the hall.
As he attempts to get a closer look, the gelatinous form of the trail congeals and forms into one cohesive being: a large Gelatinous Cube. It advances on him too quickly for him to stop it in time, and consumes him in its mass.
The rest of the party springs into action to try and save him, but the cube proves surprisingly durable. However, Stahlstrauss is able to escape with only a small amount of damage to his frame, and the cube moves on to attack the other three, gathered further down the hall. Lythanis, panicking, expends a significant amount of energy to launch the cube backwards, slamming it into the back wall of the hallway. The surrounding area shakes from the impact.
At the far end of the hall, next to where the cube crashed, another alcove exists in the corner. It is blocked by bars and contains two nearly-forgotten prisoners; a Githzerai monk wearing clothing with an elaborate design, and a Half-elf in chainmail passed out on the floor. The impact of the cube wakes them; the monk, Garmeth, rises to his feet from his sitting position, and the half-elf, one Lucan Vrinsk, awakes.
Garmeth sees the situation for what it is - the only opportunity to escape with the gelatinous cube that threatened to devour them before else occupied. He moves quickly, and is able to pick open the lock on the bars that hold them back (though it is easily picked - perhaps by design). Meanwhile, the cube advances on the party again, and engulfs Zil'dejin.
Zil'dejin is having trouble escaping, and so Lucan rushes over to assist him in getting out of the cube. Now free, Garmeth attacks the cube, alongside Lucan and Zil'dejn while the other three attack from the other side. Before long, the cube is worn down and separates from itself, essentially dying (though, it was hardly alive in the first place).
The six then decide to ensure the area is secure before exchanging any words. In an adjoining room, they find two sarcophagi. They open one inadvertently, and the other opens with it; two "corruption corpses" shamble out, masses of constantly-regenerating foetid flesh. They dispatch the corpses quickly, which explode when defeated, and move to the next room.
This room, apparently once a children's bedroom, is now mostly empty. A chest inside has, aside from the items owned by Garmeth and Lucan, some items of value including some jewelry and a Safewing Amulet +1 (taken by Lucan).
They then take the opportunity to talk. The two who were imprisoned were captured separately, but placed in the same "cell" with the threat that if they tried to escape, the cube would eat them (and, indeed, it probably would have). They were not fed or attended to for days, and were more or less left to rot in the darkened halls which had been boarded off, presumably by the hobgoblins. The party explains their reasons for being in the keep, and Garmeth agrees to accompany them until the ritual is stopped. Lucan, who is aligned with House Medani, feels a need to repay the party for freeing him, and to complete his own mission for his Dragonmarked House, though he is not at liberty to reveal what this mission is.
Now numbered at six (plus Valthrun) the party proceeds through the iron-bound doors at the intersection they passed initially. Inside, they are met with the foul stench of death and the pervading sense of imminent danger. They quickly discover that this room is absolutely filled with the dead.
The party engages in a lengthy battle with the zombies, but most are rotted and frail; they are able to cut a swath without much difficulty. Meanwhile, a small gargoyle-like messenger construct attempts to flee the scene as the dead begin to fall. The party is alerted by this, but none are close enough to reach it and stop it in time. Lucan is quite close, but not close enough, and he has no means of making a ranged attack. Instead, he takes the opportunity to demonstrate one of his many peculiar abilities: called "Dimension Swap," he folds the space between himself and the messenger, literally compressing the dimensions so they are standing inches away while before they were several yards apart. They quickly swap places and like an elastic, the space returns to normal. Lythanis is then able to stop the messenger from proceeding.
The room is quickly cleared after that. The party discovers a small tunnel in the wall; it is too small for the large Stahlstrauss and Zil'dejin to fit in, but Lythanis and Garmeth are able to get inside. The room at the end was once attached to the keep, evidently, but this is no longer so. There are some treasures here, including an unusual felt bag, which Lythanis identifies as magical. They are afraid to open it, so they take it to Valthrun to identify, though he is little use in this respect. Eventually, Stahlstrauss opts to reach inside, and pulls out some coins and a potion stored within the impossibly large depths of the bag of holding.
After this is done, the party descends a set of stairs, and stands before some ornate ironwork doors, marked with many images of demons and the like. They gather their wits and then proceed.