After they recovered from their encounter with the hydewings, the party made their way down into the depths of the catacombs. As they progressed, they were assaulted by a nauseating miasma that gave off the smell of death and decay. As they exited the stairs into a large chamber, they found the source: a chamber containing several pits of both acid and stripped off bits of flesh. As they entered, they heard a low rumble followed by some wet, squelching sounds from behind them. They turned around to see an organic barrier forming across the door. As they turned back around, they saw flesh from the pits begin to move and assemble itself into a living, pulsating mass - the abomination.
The abomination roared - an evil, utterly alien sound that rattled the chamber. Two Hydewings swooped in from above, while several ghouls rose from the flesh pits. All turned their attention to the party, which wasted no time in getting down to business.
After a grueling battle, all the enemies were defeated. The fell magic holding together the abomination began to grow into a visible aura while the corpse dissolved into a pile of entrails and gore. The magic itself let out another roar, a bigger one, crackling with energy and hatred.
The chamber began to fall apart as the barrier dissolved, revealing an army of hundreds of enraged Vermin. At the same time, a section of the wall gave way to reveal a long, relatively thin passageway. Most of the party ran for it, but Gerard stayed behind to hold off the vermin and buy his friends some time.
As the rest of the party bolted for the cave, Amusel stopped for a moment and through one last healing incantation Gerard's way before sprinting off to join the rest. Returned to full combat capability, Gerard turned to face the vermin. He threw open his coat, revealing dozens upon dozens of throwing knives, and snarled, "Go back to the shadow! You shall not pass! You shall not harm my friends! YOU WON'T TOUCH MARA!"
With that, Gerard began to unleash a hail of blades at the Vermin. Knife after knife flew through the air, striking with deadly precision. Even so, the vermin simply charged over the corpses and pushed through the barrage. When they started to get too close, Gerard began to whirl about, punching and kicking hard enough to smash bones and shatter skulls before resuming the storm of steel. Once he saw that the rest of the party had made it to the exit, he began to retreat, hurling knives as he went.
Unfortunately, as Gerard backpedaled, the falling rocks from the cavern closed off the acid pits enough that the vermin could safely run over them. Enraged at the one human who was decimating their ranks, they began to change, growing more bestial and dropping to all fours to charge straight towards the monk en masse. While Gerard still kept up his assault, it wasn't long before the enemy surrounded him.
Gerard Phoenixson smiled sadly as he realized his fate. Filling the air with knives, whirling amongst the vermin, he called to his friends, just barely out of reach, his voice calm and studious. "I have no regrets. Take care of Mara for me, and let no harm come to her. Return the book to the monastery. We were a good team. And they shall not pass." Without another word, he plunged into battle once more with a look of fire, doing his best to hold them back from escape, not a single scream escaping his lips as he fell.
As the vermin clambered over Gerard's body, the cave wall finally gave way and shattered, the separate boulders falling into a rushing underground river thirty feet below. Just before the Vermin swarmed them, they jumped to safety.
The river carried them to a cavern. As they floated into it, they heard the sound of a single pair of hands slowly clapping echoing off the walls. They made their way on to dry ground and saw that the clapping was coming from the mysterious man they'd seen speaking with Lady Borafont and the Alilei diplomats. He was flanked by a man and a woman, both of whom looked strangely, creepily blank. Each had a black mark on their neck, but the party was too far away to see it in detail.
The man introduced himself as "The Prophet", congratulated the party on their victory over the abomination, and mentioned that not even Lady Borafont knew that it was down here - she'd just expected the party to rot in their cell. He then said,
"I'm sorry to have to do this to a group as capable as you, but unfortunately you're still an obstruction. Now if you'll excuse me, I have other things to do."
With that, he shimmered and vanished, revealing that his presence had in fact been the result of a high-powered illusion spell. The people at his side, however, stayed right where they were. Their eyes rolled back into their heads and they began to twitch while a pitch-black miasma began to pour out of the marks on their necks, coating them in impenetrable darkness. As the black began to recede, a red glow began to emanate from within the cloud. Finally, the shadow solidified into two suits of plate armor - identical to the fearsome black knight that had nearly slaughtered the party earlier.