As per their agreement with Vulian Anshin, the Spellfury takes the party back to Luenath. There, the Keepers reunite with Blais, who is one of the last werewolves of the city still standing. Their patrols have grown thin and she stands watch, with a few others, over those afflicted by the Wolfplague. Blais has placed most of them into the Green Dream, a form of stasis that can greatly slow–but not halt–the disease’s progression. She mentions that they remaining werewolves have even had to allow a new prisoner to work rather than be jailed in the Dream.
The prisoner, Slott, is a goblin who once served with the Order of the Grey Star. He is preparing a superb meal for the evening, as soon as the patrol returns. It doesn’t.
Blais requests that the party search for the patrol, sending with them another recent visitor to Luenath named Lucien Lyonsbane. A paladin sworn to an oath of vengeance, he reveals to the party that he knows them far better than they know him. He received a vision of their friend Felgrin in the Abyss, and has been charged with rescuing the dwarf from a premature death in Kelemvor’s name.
The party creeps through the streets until they find one of the patrolling werewolves being munched on by a ghoul. When they move in to attack it, they’re assaulted by undead led by the succubus that they had banished back in Talath.
When the victorious party returns with the news of the patrol’s demise, Blais has them talk to Slott. He came to Luenath after escaping from the forces of two demonic cambions, the Sisters of the Scythe. They have forces guarding the pool of power that is Tenebrous, Orcus’s divinity, somewhere in the Marches of the Crinti. Slott sought to take up the powers of the god for his own purposes, and failed.
Worried over the fate of his deva and more confident in his powers than before, Thane asks Blais for a place where he can remove his ceremonial sharkskin attire and reveal himself to the world. She takes him to a pool once consecrated to Eilistraee.
While removing his bindings, Thane sees a horrific vision of the cambions, Arimandrea and Vysith, draining away his deva’s divine essence in Orcus’s name. He returns to his body to find the pool around him dry and blackened.
The Keepers decide that they must find a way to journey into the Abyss. Blais tells them of an old Crinti scroll that drew Slott to the city. It provides a focused access into the Abyss. Recognizing its power when she took over Luenath, Blais entrusted it into the care of a firbolg tribe in the woods to the northwest of Luenath. She grants Jhyr a marking that will allow him to access the scroll and prove himself as her designate.
Jhyr is confused, as he is certain that he recalls no firbolg tribes in that forest at all. The party makes their way up the coast along the Prastuil Road, running into a tortle tinker named Lumke. He has been making his way down the coast from Herath, and welcomes them into his shell-shaped traveling shop.
Once they leave the tinker behind, they enter the woods. There, Jhyr detects glimpses of the sylvan language concealed in the bends of trees. The characters are long since grown over with bark. All of the language leads them deeper into the woods, where the trees have begun to grow strange and dark. They find unmistakable signs of old firbolg habitation, including an inscription of the first firbolg oath in one of the nearby trees. The tree, actually an old treant, tries to ensnare Jhyr, but fails.
The Keepers follow the signs to an old door of living wood, which activates when they replace golden flowers that have fallen out of its face. Inside, they find a shrine to the giant goddess Iallanis, and beyond that, a twisted glade that is home to the strange and forlorn Briarbite tribe of firbolg.
The Briarbites–among them, their chieftain Balanog and his daughter Shannad–confirm that they were entrusted with the Abyssal scroll a long time ago. It corrupted their lands and began driving the people mad, but they kept their promise to Blais. After Jhyr presents his symbol, proof that Blais has marked him, Balanog says that they will not prevent the Keepers from entering the scroll’s resting place.
Wandering through the village, they meet the town’s sole druid, Brightbark. She has given in to a nihilistic worldview and is preoccupied with fungi and rot.
That night, while Ari is on watch in the quarters the party has taken on in Balanog’s tree-home, he sees strange figures walking through the village below, wearing elk skulls as helms.
The next morning comes, and the Keepers delve down into the cavern where the scroll is kept. In a room full of glowing mosses that have grown into demoniac runes, they find themselves assaulted by strange sensations and bouts of madness and confusion. Monok, especially, hears voices warning him that he will never return from the cavern.
Ari, too, experiences some hallucinations, but he finds that cryptic messages from his patron allow him to focus. The party destroys the strange mosses.
Afterward, they come upon a vast black cavern. Using Kilgruss’s Light spell, they observe an overgrown leech moving through the darkness. When Monok tries to determine how many of the creatures are there by cutting his hand, the party is attacked by leeches and giant fleas.
Down in the darkness of the caverns beneath the Briarbite firbolg village, the Keepers find themselves gripped ever more tightly by madness and unnatural terror.
They come across a stone bridge over a black, fathomless chasm. As they are making their way across, the bridge crumbles, sending them spiraling down onto a forest of rusting spikes. Several party members realize that the entire bridge is an illusion, and that in reality it is just a rise of stone over a drop of a couple feet.
Proceeding onward into the maddening tunnels, they find that the air is full of spores. They engage and defeat a monstrous servant of Zuggtmoy who is guarding what they seek: a powerful teleportation scroll.
Lucien sets eyes on the scroll, and the alien words trigger a spell that sucks the entire party into the Hells, divorcing them from their physical forms.
The Keepers find themselves on a barge on a misty river. The captain, a merrenoloth, is oddly familiar. He reveals that he is all that remains of Rysar Golenoi–a skeletal figure with a wolf’s amber eyes, his handsome face wasted away until yellowed bone protrudes. Rysar admits that he is what happens when a wicked soul stands astride law and chaos: unable to choose, he is damned to wander the waterway for eternity. The Mystrans have tried to resurrect him, but the waters of Styx are preferable to what awaits in their care.
He offers to take them to the fallen angel Zariel, Lady of Avernus and foremost general of the Blood War. When he deposits them in Avernus, they are immediately assaulted by demonic gnolls rising from the river. When they seek safety in nearby caves, Zariel and her Erinyes slaughter the remaining gnolls. Zariel recognizes divine power in Thane, and spares the Keepers a messy death.
She takes the party back to the Basalt Citadel, but whether they are prisoners or guests is not clear.
Zariel sees the value in the party, knowing that they are brave souls who will some day make formidable generals in the Blood War if they can be turned to evil. She seems patient enough to wait for that day.
More present is her desire to recover a lost asset: the arcanaloth Oromestis. A mercenary with the ability to sniff out planar rifts, Oromestis has been key to Zariel’s defense of Avernus, as he allows her to outmaneuver her enemies.
He has been taken prisoner by the brutal gnolls of Yeenoghu. Zariel provides them with a passage to the Seeping Woods, Yeenoghu’s plane of the Abyss. It is a vile and carnivorous ruin where everything hunts or is hunted.
Although they manage to fight off a small band of gnoll skulkers, they come to an area of woodland where the shadows are alive and hungry. Fleeing from the carnivorous darkness, they come to an encampment in the woods.
They take a gnoll prisoner, who tells them that the encampment’s packmaster is a sadistic shaman named Shardtooth Earthbreaker, who fell out of favor with Yeenoghu’s lieutenant Grubash Blacksnout and was banished to the woods to watch over incoming slaves from other planes.
The party infiltrates the encampment by stealth and discovers a strange prison that appears to be a patchwork of many different building techniques. There, they meet the fire genasi, Kenna, who is one of many prisoners.
Kenna requests that the party recover the prison key from Shardtooth and free the prisoners. He promises that he can be of help in their mission for Felgrin’s soul, as he is a cleric of considerable gifts.
The party is in luck. It’s a night of revels for the gathered gnolls, and they are drunkenly supping on fermented blood. After a failed attempt at infiltration, they are confronted by a drunken Shardtooth. He lives up to his name, casting a powerful Earthquake that threatens the stability of the prison and nearly slaughters the Keepers.
After putting an end to the spellcaster and his elemental magics, the Keepers recover the key from Shardtooth’s corpse. They make their way back to the prison, which is now structurally compromised. The genasi is one of the few survivors.
Searching through the ruins of the prison, the Keepers are able to find several survivors: Kenna; an aged duergar named Holm; a little girl named Lisha; a flamboyant human sorcerer, Byrim; and a human witch, Rydeen. It seems that all of Shardtooth’s captives had unusual powers.
They also discover a halfling prisoner with his throat ripped out, and suspect that one of Shardtooth’s gnolls may have survived to take vengeance.
Led by Kenna’s divination magics, the party makes their way out of the Seeping Woods and eastward toward the Gathering Gate.
There is a massive gnoll migration occurring across the Gnashing Plain. The Keepers stick to the hills, avoiding prying eyes, but as they head further east, they begin hearing and feeling an immense rumbling echoing up through the ground, one that never seems to cease. This is the movement of Vujak-Yeenog, the mansion of Yeenoghu. After they are set upon by outrunners carried by wyverns, the Keepers seek refuge in a series of caves nearby. Holm claims that he can find the way to the Gathering Gate via the plane’s Underdark.
While resting in the darkness, Byrim is killed, his throat torn out.
After the mysterious and violent death of Byrim, the party must make their way down into the shadows of the cave system. The area is enchanted with vile magics and heavily trapped. One door will not let them pass until they have supped on mortal flesh, of which there is a gruesome pile heaped outside of the portal.
The party makes their way past blinded ghouls that are poised to attack anything that makes a sound. They find that the caverns breach into a domain hallowed to Doresain, the Lord of Ghouls, whom Yeenoghu displaced as a demon prince.
Lisha has separates from the party and flees into the blackness below. The party chases her down, realizing too late that she was just a figment created by Doresain. The Lord of Ghouls has been long imprisoned and wishes the party’s aid in taking on Yeenoghu. He claims that if they assist him, he will create enough of a distraction for them to enter the palace and save Oromestis.
As a condition of his aid, Doresain wishes for the party to help him recover his ring, the Blanched Circle, from Yeenoghu, who wears it as a symbolic and literal expression of his dominion over Doresain. He tells the party that he will furnish thousands of ghouls to attack Vujak-Yeenog, but that they will have to draw Yeenoghu out themselves. He also entrusts Ari with a knife, Tisthir, made from Doresain’s own unholy bones.
During the attack, a wave of ghouls rushes the castle, but equal numbers of gnollish defenders pour forth from Vujak-Yeenog. This leaves the castle empty enough for the Keepers to infiltrate. They find an unguarded sally port and sneak inside.
The castle is not entirely empty, however, and a group of powerful demonic gnolls tries to pin down the Keepers. One of them manages to kill Kilgruss before the party can put an end to their foes.
They move on, carrying Kilgruss’s body, to find Oromestis. The arcanoloth has been badly tortured and his innate magics are in rebellion. As they are picking the locks that secure Oromestis to a torturer’s rack, he begins emitting surges of Wild Magic. One of them strikes Kilgruss’s body and reincarnates him as a small halfling woman.
With Oromestis safely in tow, the party ascends to Yeenoghu’s throne. They challenge and taunt him, easily baiting the bloodthirsty demon lord to follow them. He leaps down from the castle, throwing dozens of gnolls aside with each blow, but he does not suspect a frontal attack from Doresain.
As the two titanic figures battle before the castle, the Keepers manage to free the Blanched Circle from Yeenoghu’s collection of stolen trinkets. Doresain is restored to full power, and he easily vanquishes the injured gnoll lord.
In the aftermath, Doresain reveals that he is now ascendant. His victory has caused abstract changes to the Prime Material Plane, where evil souls will now be drawn to his worship. The power of ghouls will grow, but gnolls will diminish and weaken with Yeenoghu banished. The Ghoul King seems to honor his word, and allows the party to rest in his domain until Oromestis is well enough to travel.
Led by Oromestis, the Keepers make it back to Avernus with Holm and Rydeen in tow. They are advancing upon Zariel’s Basalt Citadel when the river begins to bubble up and countless ghouls begin to belch out onto the shores. Speaking through them, Doresain informs the Keepers that the ghouls are an offer of peace: he wishes to forge an alliance with Zariel that might shift the balance of the Blood War.
The ghouls are not the only newcomers. Moments after that pronouncement, a rift shreds the sky overhead, and several adventurers fall through. Kelshar, Khymerus, Bhediya, and Garret are members of the Harbingers. They are disoriented but generally uninjured. Because of the Keepers’ relationship with Zariel, the Lady of Avernus welcomes the newcomers to the keep and begins trying to seduce them to her service–with the notable exception of Bhediya, whose plate armor she recognizes and disdains.
While the adventurers are viewing the field of ghouls from the battlements, one of the creatures’ eyes begin to glow an unholy crimson. Orcus speaks through the creature, telling Doresain that he is a traitor. Orcus says that the ghouls will be the first of many reparations for the Ghoul King’s foolishness.
Orcus wrests control of the ghouls away from Doresain and bids them to attack the citadel. Zariel calls to her erinye attendants, and they scour the field with fire and fury. During the fighting, Zariel, Oromestis, and Monok are struck with arrows whose wounds cannot be healed.
Zariel recognizes the poison on the arrows: it comes from the Viper Forest of Zrintor on Azzagrat, one of the layers of the Abyss. Graz’zt, the ruler, was a devil who was Gargauth’s highest servant. When Gargauth was banished, Graz’zt took the Tenth Circle of Hell for himself just in time for Asmodeus to banish it into the Abyss. She says that there is no known cure.
Oromestis points out that there are liches older than time itself in the Valley of the Crypt Things, on Thanatos. At Zariel’s order, he agrees to take the Keepers and Harbingers there. They travel through another rift that spits them out near Lachrymosa, a fortress of the undead. There, Thane sees that a vast ritual is being powered by angelic grace.
They are unable to avoid detection for long, as Orcus has eyes everywhere on Thanatos. Rotting monstrosities pursue the party on their way to the valley, until the party can run no longer and are forced into a pitched combat. They are nearly defeated when a familiar voice rings out and holy fire rains down upon the undead.
Felgrin, the long-dead Keeper, has been trapped on Thanatos since his death. He escaped Lachrymosa and has avoided the undead. He knows the Valley of the Crypt-Things well. They are amoral, immortal creatures that will do anything for a price. They tell the party of a stone with infinite power over death itself, and point out a tomb where it lies.
Once the party ventures into the tomb, the Crypt Things reveal that their promise was a ruse. While the stone exists, it is old and fragile, with only a glimmer of its power remaining. The true reason was that one of Orcus’s lieutenants wished the party to be cast into her domain.
They proceed past awful traps and find themselves confronted by the cannibalistic halfling that the Keepers encountered long ago. The Crypt Things are amused at seeing the halfling’s own designs turned against her, and bestow upon the Keepers the means to save Monok, Oromestis, and Zariel.
Once Oromestis is restored, Zariel experiences a rare pang of conscience and allows the Harbingers and Rydeen to return to the Prime Material Plane. The reunited Keepers, however, find that they begin to dematerialize when they travel through the portal. It seems that they exist in the Outer Planes as mere souls, and that they are truly dead.
Holm reveals that he, too, is dead. He is the shade of Branduin Bleakshard, who was cast down to the hells after the Battle of Herath. He lost his memories in death. He says that a group looking like the Keepers came to Herath on behalf of Halruaa and attacked, assassinating Farl Gnollbone. The dwarven counterattack on Maeruhal was bloody, but the bombing of Herath by the Halruaan skyships was worse. He died keeping Halruaan mages from detonating the volcano.
He’s happy to have company in Avernus, but wishes to return to Faerun as badly as they do. Fortunately, Zariel has an answer to their hopes.