Chapter 3: The Darklake

Though its name might evoke images of a single subterranean body of water, the Darklake is a network of underground rivers, natural tunnels, and canals that connect innumerable water-filled caverns and chambers. This vast waterway stretches over a hundred miles across, with ceilings that are miles high in some places and depths that are unfathomable.

Long ago, duergar engineers extended and widened many of the interconnecting passages of the Darklake. They also constructed locks for raising and lowering watercraft to different levels within it, opening up large portions of the network for travel. Many Underdark creatures are experienced in navigating the Darklake, including the kuo-toa-fishlike humanoids known for their insane obsession with unraveling the secret patterns of the Underdark. Still, better to trust a kuo-toa guide than attempt to traverse the Darklake alone and become lost within it forever.

The adventurers can use the Darklake to reach many destinations in the Underdark. More importantly, water travel makes it difficult for their drow pursuers to track them. The kuo-toa town of Sloobludop is located on the eastern edge of the Darklake, and is a potential source of watercraft and navigational aid. But as they seek out these resources, the characters learn of terrible powers loose in the Underdark-worse than the drow, the kuotoa, or any other threat of this dark realm.

The Darklake: General Features

The following features commonly apply to the Darklake region.

Darkness. True to its name, most of the Darklake exists in pitch blackness. The only light available is whatever the characters are able to provide.

Caves and Tunnels. The Darklake is a giant labyrinth of lakes, waterways, and canals that connect myriad caverns and chambers. Some of these caverns are massive, with immeasurably deep water and vaulted ceilings far outside the range of any light. Others are narrow, with only a few feet of space between the ceiling and the surface of the water. Some are completely submerged, navigable only by those able to breathe underwater.

Navigation. Without the sky or the stars to navigate by, any successful passage of the Darklake relies on one’s familiarity with its intricate network of caverns, passages, and currents. Experienced navigators know how to find and read ancient duergar runes carved along the Darklake’s tunnels, though most of these “road signs” are nearly worn away by the passage of time. Such knowledge is something that takes years, if not decades, of wandering the Darklake to acquire.

Those without the skill to navigate the Darklake (including the adventurers) must employ maps or guides. If the characters manage to acquire a map, they can make Wisdom (Survival) checks normally to avoid becoming lost.

Foraging. The characters can forage for food while traversing the Darklake, primarily by fishing and gathering edible fungi (see “area Fungi of the Underdark” in chapter 2). Much of the water of the Darklake is unsafe to drink, making it important to seek out springs and other clean sources of water feeding into it.

Traversing the Darklake

The adventurers need to find a way to cross the Darklake on the way to their ultimate destination—out of the Underdark and back to the surface world. They might attempt to find a guide or hire passage in Sloobludop, but other possibilities could also present themselves.

Modes of Travel

The adventurers might find different ways to cross the Darklake, depending on how long they traverse it and who or what they encounter along the way.

Since there is no wind in the Underdark, all water travel involves either rowing at 1½ miles per hour, or floating with prevailing currents at 1 mile per hour. Characters can work in shifts to row more than 8 hours per day, but crewing a boat for longer than that is considered a forced march (see chapter 8 of the Player’s Handbook).

Boat

Most craft navigating the waters of the Darklake are zurkhwood vessels piloted by the kuo-tua or the duergar. These boats are equivalent to keelboats (see the Airborne and Waterborne Vehicles table in chapter 5 of the Dungeon Master’s Guide).

Makeshift Raft

Characters can also construct makeshift rafts using materials at hand. For example, the cap of a giant zurkhwood mushroom can be hollowed out to make a coracle equivalent to a rowboat, but with half a rowboat’s hit points (see the Airborne and Waterborne Vehicles table in chapter 5 of the Dungeon Master’s Guide). This is a downtime crafting activity requiring one day’s work per raft.

An even more makeshift craft might involve a character sitting in a floating barrel or other watertight container, either steering with a paddle or flowing with the current. Such a vessel has a speed of 1 mph, requires a crew of 1, allows for no passengers or cargo, and has AC 11, hp 20, and damage threshold 0.

Swimming

Swimming in the Darklake is a poor choice given the number of dangerous creatures inhabiting it. Check for a creature encounter each hour that characters are swimming, rather than every 4 hours of travel. A swimming character must succeed on a DC 10 Constitution saving throw for each hour of swimming or gain one level of exhaustion.

Characters not actively swimming but simply clinging to something that floats (including the wreckage of a boat or raft) can drift with the current at a speed of 1 mph. Check for creature encounters each hour that characters float in the water, and call for Constitution checks against exhaustion for every 8 hours of travel.

Other Options

Travelers can mix and match modes of travel, and a sizable party might need multiple boats or rafts. A creature with a swimming speed (including a polymorphed character) can travel without risk of fatigue for up to 8 hours, and can even serve as a mount for a creature smaller than it. Water-breathing (or nonbreathing) creatures can swim underwater or even walk across the bottom of shallow sections of the Darklake, but need darkvision or a source of light to see.

Random Encounter

Every 4 hours that the characters are on the Darklake, roll a d20 and consult the Darklake Random Encounters table to determine what, if anything, they encounter. If the characters aren’t moving-anchored or ashore, for example-any encounter is automatically a creature encounter.

Darklake Random Encounters

Darklake Terrain Encounters

Special terrain rules are explained after the table.

Darklake Terrain Encounters

Darklake Creature Encounters

The sections that follow the table provide additional information to help you run each creature encounter.

Darklake Creature Encounters

Collision

This terrain encounter occurs only if one or more party members are traveling by raft or boat, and there’s a strong current. Have everyone aboard the vessel make a DC 13 group Dexterity check to avoid hitting a wall or other large obstacle directly ahead. If the group check succeeds, the collision is avoided. Otherwise, the vessel takes 2d10 bludgeoning damage from the collision, and everyone aboard must succeed on a DC 10 Strength or Dexterity saving throw to avoid falling overboard.

Falls or Locks

Any character with a passive Wisdom (Perception) score of 12 or better can hear the roar of a waterfall ahead. A successful DC 14 group Strength (Athletics) check is necessary to steer or swim away from the falls. Otherwise, the characters go over, falling 1d6 × 10 feet into a pool or river 1d6 × 5 feet deep. A creature swept over the falls must succeed on a DC 11 Dexterity saving throw or take 1d6 bludgeoning damage per 10 feet fallen. A successful save indicates that the creature avoids a hard landing in the water below.

There is a 50 percent chance that any waterfall area contains a duergar-built lock designed to traverse it, in which case there is no risk of going over the falls. It takes a successful DC 11 Intelligence (Investigation) check to figure out how to operate the lock. Once a lock is opened, it takes 1 hour for the water level to lower so the party can proceed.

Island

A small island rises from the water ahead. An island with no hostile creatures makes a good place for the party to take a long rest. There is a 50 percent chance that the island has one or more types of fungi growing atop it (see “area Fungi of the Underdark” in chapter 2). Otherwise, the island is barren rock.

Low Ceiling

The clearance of the cave or passage lowers suddenly to 3 feet above the water’s surface. Each Medium character must succeed on a DC 10 Dexterity saving throw or take 1d4 bludgeoning damage from hitting the ceiling before the passage ends.

Rockfall

Loose rocks fall from the ceiling above. Each character must succeed on a DC 12 Dexterity saving throw or be hit by a chunk of falling stone for 2d6 bludgeoning damage. If the characters are traveling in a boat or raft, their vessel takes 2d6 bludgeoning damage for each successful save; in other words, each rock that misses a character hits the boat or raft instead. Roll the damage for each rock striking a vessel separately to see if it overcomes the vessel’s damage threshold.

Rough Current

The waters here are especially turbulent. If the characters are traveling by boat or raft, the crew must succeed on a DC 13 group Dexterity check to maintain control. If the group check fails, the vessel takes 2d6 bludgeoning damage, and each occupant must succeed on a DC 10 Strength or Dexterity saving throw to avoid falling overboard.

Run Aground

This terrain encounter occurs only if one or more party members are traveling by raft or boat. The vessel hits a shallow area or sandbar and runs aground. The characters can push the vessel back into the water with a successful DC 10 group Strength (Athletics) check. While characters are pushing their boat free, there is a 50 percent chance that one or more creatures attack them; in this event, roll on the Darklake Creature Encounters table to determine what attacks.

Stone Teeth

This terrain encounter occurs only if one or more party members are traveling by raft or boat, and there’s a strong current. Stalagmites jutting up from the bottom of a tunnel are hidden just below the waterline. Spotters must succeed on a DC 13 Wisdom (Perception) check to notice the “stone teeth,” allowing the vessel’s crew to attempt a DC 12 group Dexterity check to navigate through them. If the group check succeeds, the vessel passes through unscathed. Failure to notice or navigate through the stone teeth deals 6d6 piercing damage to the boat or raft.

Tight Passage

The adventurers encounter an especially tight passage, requiring a successful DC 12 group Dexterity check to navigate a boat or raft through it. If the group check succeeds, the boat slips through. Otherwise, the boat gets stuck, requiring a successful DC 14 group Strength (Athletics) check to push it free. While characters are pushing their boat free, there is a 50 percent chance that one or more creatures attack them; in this event, roll on the Darklake Creature Encounters table to determine what attacks.

Whirlpool

An underwater crevasse or drain creates a small vortex in this area, much like the whirlpool effect of the control water spell (save DC 14).

Aquatic Troll

An aquatic troll swims up from the depths. It has the abilities of a normal troll, but can also breathe water and has a swimming speed of 30 feet.

Darkmantles

These creatures cling to the ceiling as the adventurers approach, cloaking themselves in darkness as they unfurl and attack. A creature in a boat or on a raft that tries and fails to detach a darkmantle from itself or another creature must succeed on a DC 10 Dexterity saving throw or fall out of the vessel and into the water.

Duergar

A keelboat crewed by duergar is traversing the Darklake on business. The gray dwarves parley with the adventurers-or attack them if the opportunity looks ripe to capture them and sell them as slaves in Gracklstugh. If the duergar surprise all the characters, they turn invisible, making it appear that their boat is abandoned so as to lure the adventurers on board before they attack.

Roll a d20 and consult the Duergar Keelboat Cargo table to determine what, if anything, the duergar are transporting in their keelboat.

Duergar Keelboat Cargo

Green Hag

Nanny Plunk is a green hag who likes to taunt and lead travelers astray. She might instead bargain with the characters with her knowledge of the Darklake, especially if her life or freedom is at stake. If this encounter occurs again, it might be with Nanny or one of her sisters, Maven Delve or Dame Spiderwort.

Grell

A grell descends from the cavern ceiling, attempting to grab and paralyze one party member, then fly off with its victim.

Ixitxachitl

These creatures attack any party members in the water. Otherwise, they follow the party and wait for an opportunity to strike. If denied a meal for too long, they begin to gnaw on the hull of a boat or the underside of a raft, hoping to sink it (this tactic is ineffective against craft with a high damage threshold).

Kuo-toa

These kuo-toa pole a keelboat toward Sloobludop (or away from the town if it has been attacked; see the end of this chapter). If the characters have not been to Sloobludop, the kuo-toa might try to capture them and bring them there. See “The Day’s Catch” for details. Roll a d20 and consult the Kuo-toa Keelboat Cargo table to determine what, if anything, the kuo-toa are transporting in their keelboat.

Kuo-toa Keelboat Cargo

Merrow

These worshipers of Demogorgon have been driven into a frenzy by his arrival in the Underdark. They immediately attack, trying to capsize or wreck boats as they utter the war cry, “Blood and salt for the Prince of Demons!” in Abyssal.

A merrow can use its action to capsize a boat or raft within 5 feet of it. Anyone in the boat can thwart the merrow by using a reaction to make a Strength check contested by the merrow’s Strength check. If the merrow wins the contest, the vessel capsizes.

Stirges

These stirge cling to the ceiling like bats. If the party is aware of the stirges, the characters can make a DC 13 group Dexterity (Stealth) check to slip past the stirges without disturbing them. If the group check succeeds, the stirges ignore the party. Otherwise, the stirges descend and attack the nearest party members.

Swarm of Quippers

A swarm of quippers keeps pace with the characters, attacking anyone in the water. If an hour passes and no meal has presented itself, the quippers stop following the party.

Water Weird

Bound to some long-lost site beneath the surface of the water, this neutral evil elemental rises to attack when the characters pass by.

Roll a d6 and consult the Weird Discoveries table to determine what the water weird is guarding.

Weird Discoveries

Sloobludop

Population: 500 kuo-toa

Government: The archpriest Ploopploopeen once ruled in the name of the Sea Mother, the goddess Blibdoolpoolp. He was recently challenged and displaced by his daughter Bloppblippodd, archpriest of Leemooggoogoon the Deep Father.

Defense: All kuo-toa rally to the village’s defense, including whips and monitors serving the priesthood.

Commerce: The kuo-toa trade with various races of the Underdark near the Darklake, in addition to providing ferry service and navigation.

Organizations: Two major shrines and several other minor ones.

Sloobludop is a kuo-toa village on the eastern edge of the Darklake. From a distance, it looks like a massive tangle of reeds stretching up into the darkness, lit by glowing spots of phosphorescence. Upon closer approach, a series of rickety towers can be seen, lashed together by rope and plank bridges set in haphazard patterns. Even above ground, the kuo-toa build in line with their three-dimensional aquatic sensibilities, constructing their “great city” as if it were underwater.

Sloobludop simmers with religious fervor and sectarian tension. While many of the kuo-toa still worship the goddess Blibdoolpoolp, a faction has shifted its worship to Leemooggoogoon the Deep Father, a vision influenced by the manifestation of the demon prince Demogorgon from the depths of the Darklake. Initially, the archpriest of Blibdoolpoolp tolerated this-but then his own daughter declared herself an archpriest of Leemooggoogoon, and the cult began to grow.

Slouching Toward Sloobludop

The characters can choose to go to Sloobludop for several reasons:

• They need a boat (and possibly a guide) to navigate the Darklake. Travel along the waterways of the Darklake is an excellent way to throw off their drow pursuers (see chapter 2 for details).
• Staying a short while in Sloobludop can provide a respite from pursuit, since the drow are reluctant to provoke the kuo-toa needlessly. Reduce the pursuit level by 1 while the characters consider their next move.
• The characters need supplies and equipment, and hope the kuo-toa might be willing to trade for whatever they can offer. Alternatively, the characters might try to steal what they need from the kuo-toa.
• Shuushar might point out any of the previous reasons, or wish to go to Sloobludop to rejoin his people, feeling he has important guidance to offer them.
• Shuushar might not be the only one with “higher guidance.” One or more characters might experience dreams or visions guiding them toward Sloobludop-not realizing that such dreams are simply further manifestations of the madness growing in the Underdark.

Notable Kuo-Toa in Sloobludop

A number of important kuo-toa have the ability to influence the adventurers' fate in Sloobludop.

Shuushar Connection

If Shuushar accompanies the party, the kuo-toa monk can be helpful in communicating with his people at Sloobludop. However, keep in mind that Shuushar is either a heretic or a holy man depending on which kuotoa he’s speaking to, and how they view things at that particular moment. The mysterious monk could serve as an ace in the hole to help the party out, or he could just as easily cause trouble with his stubborn refusal to acknowledge his fellow kuo-toa’s religious obsessions as anything other than “dangerous illusions,” combined with his preference for nonviolent solutions.

Roleplaying the Kuo-Toa

Though the kuo-toa are mad, at least some of that madness comes from an utterly alien mind-set. Although amphibious air dwellers, the kuo-toa still largely behave as aquatic creatures. Thus, much of what they do on land is a bizarre approximation of life under the water.

Kuo-toa names are a long series of gargling syllables, and their voices have a bubbly, gargling quality. However, the kuo-toa communicate as much through gesture as speech. They have difficulty standing still, and are prone to quick, darting movements. They pace constantly, walking in circles around creatures talking to them. A kuo-toa priest speaking to a group of followers doesn’t stand at a podium but wanders aimlessly while the crowd follows like a school of fish.

Kuo-toa prefer their leaders to be physically above their subordinates. (If no dais or platform is available for leaders, they have been known to literally stand on top of prostrate underlings.) However, leaders tend to dwell on the lowest levels of buildings because these are considered the safest areas in a settlement, due to their proximity to the water.

Since the kuo-toa are fishlike, they lack eyelids. This isn’t only unnerving in conversation (a kuo-toa never blinks), but it also means that kuo-toa all look the same sleeping as awake-and virtually all kuo-toa sleepwalk, making things even more confusing. There is a 25 percent chance that any individual kuo-toa the party encounters in Sloobludop is sleepwalking, ignoring everyone around it and moving in a shuffling gait from place to place.

Sloobludop: General Features

Sloobludop spreads out along the rocky shore of the waters of a broad cavern lake, with high fences of woven netting to the north and south of the village boundaries.

Light. Sloobludop’s cavern is almost entirely dark except for a few spots of dim light from phosphorescent fungus and coral, or from glowing cave-fish glands. The kuo-toa recoil from areas of bright illumination, becoming hostile if bright light is brought among them.

Bridges and Platforms. Bridges and platforms are haphazardly strung throughout the city, connecting various levels of structures with each other as well as crisscrossing open spaces. Characters can move at a normal pace across the platforms and bridges, but this puts strain on their poor construction. Whenever one or more characters move at normal speed across a bridge or platform, roll a d6. On a roll of 1, a bridge flips or breaks to drop characters to the platform below, or a platform tilts to tip the characters into the water. These areas can be navigated safely by treating them as difficult terrain.

Language. None of the inhabitants of Sloobludop speak Common or any surface-world language, which might present a challenge for the characters. The fish-folk speak Undercommon, and Stool the myconid sprout can establish communication using its rapport spores if it is present. Shuushar the kuo-toa monk can also translate if he accompanies the party.

The Day’s Catch

When the adventurers come within an hour’s travel of Sloobludop, they encounter a party of eight kuo-toa led by a kuo-toa monitor. The fish-folk immediately attack, but their tactics show that they are attempting to capture the characters. The kuo-toa leave any fallen opponents unconscious at 0 hit points, intending to bring them back to Sloobludop as live offerings to the Deep Father. They bind prisoners with tough cords of gut, each with 2 hit points and requiring a successful DC 17 Strength check to break.

The Enemy of My Enemy

On the way to Sloobludop after the previous encounter, the characters run into another kuo-toa patrol, this one made up of six kuo-toa and two kuo-toa monitor, led by the kuo-toa archpriest Ploopploopeen. If the characters are prisoners of the first kuo-toa patrol, the newcomers ambush them and fight to free the characters. Otherwise (or after the fight), Ploopploopeen attempts to communicate in Undercommon, then casts tongues if none of the characters speak it. Read the following:

“I am Ploopploopeen, archpriest of the Sea Mother Blibdoolvpoolp. She answers my prayers by delivering you. Help us, and you will be rewarded for your service.”

If the characters talk with Ploopploopeen, the archpriest explains his intentions as the kuo-toa escort the party to Sloobludop. If the characters refuse, the kuo-toa attempt to capture them, as with the previous patrol.

Ploopploopeen explains that the inhabitants of Sloobludop have lived in harmonious service to the will of the Sea Mother for some time. Oh, there were occasional “visionaries” who stirred up trouble (at this, he might cast a walleyed glance at Shuushar) but nothing of any great concern. A few weeks ago, Bloppblippodd, Ploopploopeen’s own daughter, experienced a powerful vision of “Leemooggoogoon the Deep Father,” proclaiming him the new god of her people. She has backed up her claims with a great increase in her magical power, and new followers have flocked to her.

“We are split in two,” Ploopploopeen explains, “fighting among ourselves.” The followers of the Deep Father have been making an increasing number of offerings on his altar-killing blood sacrifices then casting bloody chum into the waters of the Darklake, where it is consumed by… something.

A Kuo-Toan Koan

The kuo-toa are aquatic creatures. As such, they have no real need for the boats they use to ply the Darklake, even as boating remains a significant part of their culture.

It might well be that the kuo-toa’s former masters-the mind flayers-used them as ferry pilots and navigators in the Underdark, and the fish-folk continue to do so out of habit or some deep-seated need. Certainly, their relative usefulness to the other races of the Underdark has served the kuo-toa well. Only the duergar have shown any interest in navigating the waters of the Darklake on their own, and not even they do it as well as the kuo-toa.

There is a persistent myth among the inhabitants of Sloobludop that the maze of tunnels, passages, and pools of the Darklake is a kind of meditation-a spiritual journey. Kuo-toa who navigate that maze long enough will awaken to a great revelation for their people. As with many of the strange beliefs of the kuo-toa, this one might only need time to become a reality.

Baiting the Hook

The archpriest of the Sea Mother tells the characters he wants to use them as bait. The archpriest of the Deep Father needs humanoid sacrifices, and the party represents a prize collection in that regard. Ploopploopeen will offer the characters as a “token of peace and reconciliation” to get closer to the archpriest of the Deep Father-except the adventurers will not be helpless prisoners, but infiltrators. Ploopploopeen wants the characters to disrupt the upstart faction’s rituals, allowing his true believers of the Sea Mother to cut off the head of the cult. The archpriest promises that the characters will be “well rewarded” for their aid.

If the characters refuse, Ploopploopeen tries to turn them over anyway, still using them as bait to get his own kuo-toa loyalists closer to his daughter’s cult. However, he no longer depends on or supports the characters as allies, leaving them to survive on their own.

No matter whether the characters approach the final encounter as willing participants or prisoners, the kuotoa make no effort to bind them or take their weapons, believing in the power of their superior numbers and the divine might of their competing gods.

1. Gate

Sloobludop is enclosed to the north and south by outer “walls” of heavy netting with sharp bone hooks woven into them. In the middle of each wall is a gate through which creatures can safely pass. Any creature wishing to crawl through the netting can do so with a successful DC 15 Dexterity (Acrobatics) check. On a failure, the creature takes 1d8 piercing damage and becomes restrained in the netting, requiring a successful DC 12 Strength check as an action to break free.

Stationed outside each gate are four kuo-toa whip. They confront anyone who approaches. Party members escorted by other kuo-toa can pass through the gate unchallenged. If the characters are unescorted, any kuotoa they meet attempt to capture them. Roll a d20. On a 1-7, captives are taken to area 3. On an 8-18, captives are taken to area 4. On a 19-20, the guards are evenly split and immediately begin to brawl for the right to take the characters as prisoners.

2. Docks

A half-dozen kuo-toan keelboats are moored here. Although kuo-toa will negotiate terms for ferrying the characters across the Darklake, none leave without permission (see below). Party members can attempt to steal one or more of the boats, but doing so requires a successful DC 16 Dexterity (Stealth) check (and the kuotoa are able to sense invisible creatures). The kuo-toa pursue any stolen boats, intending to capture the thieves as offerings to appease their gods.

Five groups of three kuo-toa monitor led by a kuotoa whip patrol the platforms at the water’s edge. They ensure no vessel enters or leaves without submitting to “auguries” to determine if a crew’s actions are pleasing to the god of the hour-in this case, the Deep Father.

The auguries consist of a half-hour ritual, during which the whip casts bones, shells, and other tokens and reads the resulting omens. Roll a d20. On 1-8, the whip finds the omens favorable; on 9-18, he finds them unfavorable; and on 19-20, the auguries are unclear, and the whip feels the need to consult the archpriest of the Deep Father (area 4).

If the characters met or spoke with the archpriest of the Deep Father before coming here, the whip automatically refuses their request to leave.

3. Shrine of the Sea Mother

When the characters arrive here, on their own or escorted, read the following to the players:

A nine-foot-tall statue stands here. Its body is roughly carved from some kind of wood in the shape of a humanoid female, its head and forearms formed from the severed head and claws of a giant albino crayfish. These parts are lashed on with strands of gut, and emit an overpowering stench of rotting shellfish. Shells, brightly colored stones, mushrooms, and rotting fish are piled at the statue’s feet and strung in garlands around its neck. Four stern kuo-toa slowly circle the statue, alert and on guard, while a few others mill about, gazing up at the statue and bowing repeatedly while chanting.

All creatures that come here are expected to make an offering to the Great Sea Mother Blibdoolpoolp. A successful DC 13 Intelligence (Religion) check recalls that Blibdoolpoolp is a scavenger goddess, meaning that discarded and recovered items are worthy offerings—and the more personal the better. Regurgitating at the goddess’s feet is considered a sincere show of faith (and a behavior faithful kuo-toa might display if the characters wait long enough).

Four kuo-toa monitor guard the statue at all times, and there are always 2d4 kuo-toa worshipers around it offering prayers. Currently the shrine is tended by Glooglugogg, a kuo-toa whip and son of Ploopploopeen, the archpriest of the Sea Mother. The guards are wary of anyone, including other kuo-toa, due to recent tensions.

Ploopploopeen claims a small hovel adjacent to the shrine, where he is attended by four kuo-toa. This is where he brings the characters if they are his “guests.”

Treasure

The home of the archpriest contains a closet full of “offerings” taken from less fortunate travelers or culled from the depths of the lake. This includes 500 cp, 2,000 sp, 150 gp, 27 pp, a strand of matched pearls worth 1,000 gp total, two potions of healing, a potion of water breathing, and a spell scroll of light.

4. Altar of the Deep Father

When the characters visit the altar of the Deep Father, read the following to the players:

The idol to Leemooggoogoon the Deep Father consists of a large hide cut roughly in the shape of a manta ray and stretched out on cords between two support poles. A dead, splayed-out manta ray is pinned to the center of the hide. Two dead octopuses are draped across the top, their tentacles pinned and artfully arrayed, their heads tied together and painted with red and blue pigments. The idol reeks of decay, and the broad stone altar below the idol is stained dark with blood.

Six kuo-toa work at the altar, cleaning up and arranging offerings. Klibdoloogut, a kuo-toa whip dedicated to the Deep Father, stands in front of the altar with two kuo-toa monitor. Offerings are usually living creatures killed on the altar, although an offering of one’s own blood also satisfies the whip. Humanoids other than kuo-toa are immediately taken into custody to be brought before the archpriest of the Deep Father, who summarily condemns them to be sacrificed.

Bloppblippodd, a female kuo-toa archpriest of the Deep Father, lives on the bottom floor of a squat hovel near the altar. She is a bloodthirsty sadist absolutely assured that her divine vision will raise her in glory to rule her people. Bound and gagged against the far wall is a duergar prisoner (see “The Offering”).

Treasure

Bloppblippodd’s hovel contains wealth accumulated since her rise to power: 1,000 cp, 500 sp, 290 gp, an embroidered silk handkerchief with a spider design worth 25 gp, three azurite gems worth 10 gp each, a duergar-made bronze cup worth 25 gp, and a silver choker with a spider design worth 30 gp.

The Offering

If allowed to do so, Ploopploopeen brings the characters to his quarters near the Shrine of the Deep Mother. There they meet Glooglugogg, who loudly tells his father in Undercommon that he sees no need for outsiders to be involved in sacred matters. The archpriest dismisses his son’s concerns with a negligent wave, telling Glooglugogg that he must flow with the currents of the goddess’s visions. The whip relents but throws the characters a hostile glare.

Within the hour, twelve kuo-toa led by a kuo-toa monitor arrive at Ploopploopeen’s quarters. The archpriest of the Sea Mother admits the monitor and informs him that he, his whip, and the prisoners will accompany them to see the archpriest of the Deep Father. They are escorted to the altar of the Deep Father near the docks, where Bloppblippodd awaits them. Describe the scene to the players as given in that area, then read the following boxed text; if none of the characters speak Undercommon, the exchange is gibberish to them, though Shuushar can translate.

The archpriest of the Sea Mother steps forward across the span of the altar toward the kuo-toa waiting for him there. “The time has come,” he says, “for us to acknowledge your divine vision and welcome it. I have brought these as offerings.” He gestures toward all of you, standing within a circle of guards behind him. “Will you not accept them?”

“You are wise, father,” the younger archpriest replies. “I accept your offering in the name of the Deep Father. May their blood nourish and strengthen him!” A burbling cheer goes up from the surrounding kuo-toa, their fists raised in the air.

The followers of the Deep Father are already preparing to sacrifice a bruised and bedraggled duergar named Hemeth-an arms smuggler who was looking to cut a deal with one or both factions of the kuo-toa, but instead found himself captured for his trouble. He’s willing to cooperate with the characters to save his own skin, and will even return the favor given the opportunity (see chapter 4, “Gracklstugh”).

The Ritual

Kuo-toa parade around the altar in a wide circle as they chant. Part of their path sends them splashing and wading through the shallows of the Darklake. The characters quickly can’t tell one faction of fish-folk from the other, but they see the archpriest of the Sea Mother and his whip moving toward the altar.

Bloppblippodd calls for the sacrifices to be brought forth, and one kuo-toa per character jumps to do her bidding. They prod the characters with their spears to herd them toward a slight depression 20 feet from the altar, with a large grate at its center. The characters can see that the stonework of the depression is stained with the blood of innumerable sacrifices, and they can hear the gentle lapping of the Darklake coming up through the grate. The chanting grows louder.

When the sacrifices are brought forward, Bloppblippodd gestures toward the altar, whereupon her father suddenly attacks, striking her with his scepter. Kuo-toa loyal to him surge forward to attack, while the guards that brought the characters forward stand in shock. They are surprised and can’t move or take an action on their first turn of the combat, and they can’t take reactions until that first turn ends.

As the two archpriests and their followers fight, the characters can intervene on either side or attempt to slip away during the melee.

On round 3 of the fight, characters notice kuo-toa crying out and flailing in the shallows of the Darklake. Several are pulled under or strike at unseen foes beneath the surface. The water foams red with blood.

Dozens of ixitxachitl are responsible for the attacks in the water. They have been drawn by the kuo-toa ritual and feast on any creatures they can reach, including party members in the water. The sudden frenzy sets a wave of panic through the kuo-toa. The young archpriest calls out “Leemooggoogoon!” just as her father strikes a final, fatal blow, dropping her before the profane altar. (If any character is also engaging the archpriest of the Deep Father, allow that character to strike the final blow.)

Demogorgon Rises!

Although Bloppblippodd falls, the ritual still achieves a terrible success. Read the following:

Another sound rises above the burbling cries of the kuotoa. The dark surface of the water farther out bubbles and begins to foam. A thick, oily tentacle bursts forth, followed by another. Then two monstrous heads break the surface, both resembling hideous, angry baboons with wickedly curved tusks. Both heads are attached to a single torso, and the monster’s red eyes burn with bloodlust and madness. The creature rising from the Darklake must stand thirty feet tall or more, with water cascading down its back and shoulders. Upon reaching its full height, the great demon throws back both its heads and roars!

The kuo-toa offerings and the fervor of his worshipers in the Darklake have drawn the attention of Demogorgon. Upon witnessing the rise of the Prince of Demons, each party member must succeed on a DC 13 Charisma saving throw or gain a level of madness (see “Madness” in chapter 2). The kuo-toa become incapacitated for 1d10 minutes, crying out “Leemooggoogoon!” over and over again.

Demogorgon wades toward Sloobludop, heads roaring and gibbering, tentacles flailing and smashing the water. In 4 rounds, he comes within reach of the shoreline and lashes out, smashing docks and sending bodies flying with each sweep of his tentacles. When the demon lord attacks, some kuo-toa recover their wits enough to flee, while others cower, paralyzed with fear.

Escaping the Demon Lord

Hopefully, the players exercise the better part of valor and flee as soon as they see the demon lord. If they confront him, they are almost certainly doomed. Fortunately for them, Demogorgon is focused on smashing the kuo-toa settlement and pays little heed to the puny creatures fleeing from him. The characters thus have a good chance of getting away if they act quickly. They might first need to deal with companions overcome by bouts of madness, however, and they need to decide how they intend to escape.

Escape by Land. Fleeing by land requires dodging terrified kuo-toa, and even fighting fish-folk driven to a killing frenzy against the characters for having drawn this doom down upon them. Roll a d20. On a 17-20, 2d4 kuo-toa attack the characters during their escape.

Escape by Water. The adventurers can steal boats from the docks and paddle them along the shore away from the attacking demon lord. The ixitxachitl attack anyone in the water, but most are occupied with slaughtering kuo-toa fleeing into the Darklake. A near miss from one of Demogorgon’s tentacles might require each character to make a DC 10 Strength or Dexterity saving throw (player’s choice), with failure indicating that the character has been thrown overboard by a wave.

Development

The adventurers end this chapter with a terrible realization: Demogorgon is loose in the Underdark! Initially, they might blame the kuo-toa ritual or the ixitxachitl. But as they learn more about what has happened, the need to escape the Underdark becomes even more urgent.

XP Awards

In addition to the XP awards earned for the creatures the party overcomes in this chapter, the characters earn 400 XP (divided equally among all party members) for surviving the encounter with the Cult of the Deep Father and their brush with the Prince of Demons.