The Drowned Dragon
The Drowned Dragon is a game-ready dungeon designed for levels 7 and 8. It features a flooded dwarven keep that is now the lair of a young black shadow dragon and its shadowfell minions.
The dungeon is built so that it's entrance can be easily fit anywhere in your campaign. It could be located in an obscure mountain pass, beneath ruins in a swamp, or beneath an active dwarven settlement.
This dungeon uses content from the Monster Manual, Mordenkainen's Tome of Foes, and Dungeon Master's Guide.
What's Happening Here?
The dwarven stronghold of Grauvenbode was home to numerous craftsmen until a terrible accident occurred. One of the craftsmen's experimental devices detonated in a massive explosion. The resulting devastation destroyed most of the stronghold and ruptured its cistern, causing the ruins to flood under a torrent of cold water. The dwarven population all died that day, either from the explosion or from drowning. The death and despair was so strong that it opened a portal to the Shadowfell in the heart of the ruins. Some years later, a young black shadow dragon named Noxidus emerged from the portal, laying claim to the ruins as his new lair. Noxidus has ruled here since, occasionally venturing outside to gather treasure for his hoard.
Who is Present?
Noxidus
Noxidus is a Young Black Shadow Dragon from the Shadowfell. The dread essence of that plane has seeped into the dragon, suppressing all of its emotions save for one: loneliness. The dragon feels constantly empty and alone, yet only knows how to connect with others through violence and battle. Noxidus feels alive during battle and never seeks to end it quickly, preferring to drag out an encounter with enemies for as long as possible. Noxidus finds temporary solace in brooding over his hoard, but forever waits for his next chance to fight and feel again.
Noxidus uses the statistics for a Young Black Dragon with the following changes:
- He has the Shadow Dragon template applied to him.
- He has 195 hit points.
- Innate Spellcasting: Noxidus' innate spellcasting ability is Charisma (spell save DC 13). He can innately cast the following spells, requiring no material components:
- 1/Day Each: darkness, invisibility
- Noxidus has access to the Lair Actions of a black dragon so long as he is within the dungeon.
Tactics: Noxidus' CR indicates he should be an Easy encounter for a party of this level. However, played tactically, Noxidus should prove a terrifying and deadly foe.
Noxidus is not encountered in just a single room. Instead, Noxidus should be present throughout the entire dungeon, fighting using hit-and-run tactics. Consider using the following tactics:
- Noxidus uses his Item Interaction to pick up a piece of broken stone or rubble in one claw and casts darkness on it. Noxidus carries the stone with him throughout combat, keeping himself permanently in magical darkness. While in this darkness Noxidus can use his blindsight to fight, and his Living Shadow trait gives him resistance to most damage types. After using his innate spell, he can also use his lair action to replicate this effect, although this darkness will not move with him.
- Noxidus hides from the party, waiting for them to pass, then emerges to launch his breath weapon at them from its maximum range of 30 feet. He then uses his full flying speed to retreat to the opposite side of the dungeon into shadow and uses his bonus action to take the Hide action.
- Noxidus waits underwater and uses his lair action to drag the party into the water with him. He launches a barrage of attacks, darting in and out using his swim speed and never ending a turn adjacent to an enemy. If the party leaves the water, Noxidus retreats and tries again later.
- Noxidus uses invisibility and stalks the party. When they enter combat with another group of monsters, he waits for one round before attacking one of the back-line members. He retreats after the other monsters are slain.
- Noxidus waits 120 feet from the party and uses his cloud of swarming insects and grasping tide lair actions to harry the party from a distance.
Algaetooth Sisters
The Algaetooth Sisters are a coven of three Sea Hags. They came to Grauvenbode a year ago, drawn to study the strange magic of the Shadowfell portal. They have reached an amicable relationship with Noxidus, who appreciates the company and the useful divination magic they provide for him. They are also capable of summoning Sorrowspawn.
Adventure Hooks
- Dragon Attacks: Noxidus occasionally leaves his lair to seek out a fight and revel in the satiation of his loneliness. These attacks can be destructive and terrifying, and locals look towards a seasoned adventuring group for aid in slaying the beast.
- Lost Wonders: The dwarves of Grauvenbode created remarkable pieces of art in their time. A dwarven historian named Baern Broodfist hires the party to enter the ruined stronghold and retrieve one of its most significant treasures: the battle-axe of Faulthra Grauven.
- Shadowfell Portal: Occasionally, undead and sorrowspawn emerge from the ruins of Grauvenbode to wreak havoc on the countryside. Scholars agree that they must be emerging from a shadowfell portal somewhere in the dungeon, and task a group of adventurers with locating and, if possible, closing the portal.
- Missing Adventurers: A band of six dwarven adventurers calling themselves the Jotungarde Valkyries went on a quest to slay the shadow dragon. They entered the ruins of Grauvenbode a week ago and haven't returned. The party is tasked with finding out what happened to the missing dwarves.
General Features
The dungeon is built from blocks of crystalline diorite, a white stone speckled by large chunks of black crystal. Hallways are ten feet wide and ten feet tall. Rooms are 20 feet high unless otherwise specified. The dungeon is unilluminated.
Regional Effects: Noxidus' magical presence creates the following regional effects throughout the dungeon.
- Pools of water are cold and murky and supernaturally fouled. Enemies of the dragon that drink such water regurgitate it within minutes.
- Cold fog lightly obscures the land within the lair.
- Darkness is thick and smothering. Nonmagical light sources shed bright light and dim light for half their usual distance.
1. Broken Gateway
A wide stairway leads down to this room from the dungeon's entrance. Wide alcoves to the east and west contain 15-foot tall stone statues of dwarven warriors holding battle-axes. A 15-foot tall set of double doors to the south has been blown off of its hinges and now rest on the floor. Fog swirls through the chamber, and a faint unnatural moaning echoes throughout the chamber.
Creatures: The source of the moaning is a single The Lost and four The Wretched, Sorrowspawn from the Shadowfell that hide behind the eastern statue. Remember that the fog lightly obscures the area, imposing disadvantage on visual Wisdom (Perception) checks and a -5 penalty on passive Perception scores.
The Sorrowspawn were placed here by the Algaetooth Sisters as door-guards. The Lost wears a Hag Eye on a rough twine necklace, allowing the hags to watch the entrance. The Sorrowspawn wait for creatures to move into the room before trying to ambush them. They fight to the death.
2. Hall of Arrivals
This chamber's roof is supported by four cracked stone pillars. The southern wall has broken inward, revealing Room 3 beyond. Two hallways stretch out from this room, one to the east and one to the west. The hall to the west has had its roof collapse, completely blocking the end of the passage.
Event: Noxidus' Welcome: Noxidus rests beneath the water in Room 3. If he becomes aware of the party's arrival in Room 2 (such as from the sound of combat or his Passive Perception beating the group's stealth check), he silently swims towards the party, staying below the surface. He then begins to speak while remaining underwater, his voice muffled and sourceless:
"You've come. I'm glad. I've been so lonely. So very lonely. Come, stay a while. Let me enjoy your... company."
Noxidus then bursts from the water into Room 2 and attacks. He remains for only one round, at the end of which he moves his fly speed south out of the party's light and dives under water, taking the hide action as a bonus action. As he departs, he calls back to the party:
"Don't be lonely. I promise, I won't leave you alone for long. I'll be close; so very close."
He will stalk the party for the remainder of the dungeon, staying hidden and out of their light as much as possible.
3. The Lake
This wide chamber is completely flooded, the ceiling and walls blackened by an ancient explosion and mist curling from the water's surface. The blasted stone ceiling rises 15 feet above the surface of the water. The water itself descends to be 50 feet deep in the center. The bottom 20 feet of the water are filled with magical darkness, as per the darkness spell.
The darkness is a one-way portal from the Shadowfell. Creatures from that plane can enter the material plane through it, but it cannot be used to travel to the Shadowfell. The Detect Magic spell senses powerful conjuration magic coming from this portal. A paladin's Divine Sense ability senses countless undead through the portal.
Magical lights cast from spells of 3rd level or higher dispel the portal where the light overlaps with it. Dispelling the entire area of darkness in this way permanently closes the portal. The Moonbeam spell or Sunbeam spell also instantly dispell the portal.
4. Pool of the Drowned
The stench of death fills this chamber. The round room is broken in the north, opening into a sinkhole that is filled with mirror-smooth black water. Five bloated dwarf corpses float face-down in the water.
Creatures: The five corpses are Ghasts. If any creature touches one of them or disturb the surface of the water, all five immediately lurch into motion and attack. Have the ghouls roll Dexterity (Stealth) checks contested by the party's passive Perception to determine surprise. If they succeed in paralyzing a character, they grapple it (succeeding automatically on their check) and drag them under the water.
These ghasts are the animated remains of five of the six members of the Jotungarde Valkyries, an adventuring party that entered the dungeon a week ago seeking to slay Noxidus.
5. Old Meeting Room
This room is empty save for the broken remains of tables and chairs, now little more than soggy pieces of lumber.
Creature: Huddled in a corner of the room is a trembling, starving dwarf. She is the last living member of the adventuring party the Jotungarde Valkyries, and she has gone mad from fear and shock. She tries to hide from the party, terrified they are enemies.
She can be calmed with soothing words and a DC 15 Charisma (Persuasion) check. If calmed and talked to, she can impart the following information:
- Her name is Maerah and she came here with her companions to hunt Noxidus.
- The dragon repeatedly attacked and retreated, wearing the party down over several days.
- The dragon seemed to like talking to them and always mentioned loneliness, company, and feeling alive near the dwarves.
- There were a trio of terrifying women who rose from the water to mock the dying adventurers.
Maerah cannot remember much of the dungeon's layout, nor warn the party of upcoming dangers. She can be cured of her madness by a Greater Restoration spell, but otherwise is permanently jittery and paranoid.
6. Hag Hallway
This corridor's eastern wall is broken open to reveal a flooded sinkhole. The water is 40 feet deep and its surface is 10 feet below the low ceiling of this collapsed space. Thick underwater weeds grow in this space and algae grows thick along the walls.
Creatures: The Algaetooth Sisters, a coven of three Sea Hags, reside in the sinkhole. The hags are cruel and malicious creatures who seek to harness the powers of the Shadowfell portal to summon and dominate Sorrowspawn minions. The first of these have already been successfully summoned and are stationed in Room 1.
Each of the three hags is the master of a weird and obscure magic known only to her. These magics are powerful, but are unwieldy and can't be used in combat:
- Smeelah The Bubbler, a wraith-thin entity with long green hair who can shrink and trap her victims in tiny bubbles.
- Cackling Molesnatcher, a warted and corpulent creature who knows how to transform the appearance of other creatures.
- Grisel Wretchwreath, a dark and terrifying woman with glittering black eyes who can manifest a semi-real simulacrum of the deepest fears of a creature.
The hags likely are aware of the party's arrival in the dungeon thanks to their Hag Eye carried by the Sorrowspawn in Room 1. The hags use their scrying spell to watch the party's progress and search for weaknesses to exploit.
The hags' goal is to protect the Shadowfell portal. If the party seems to be coming close to destroying it, the hags will attack. Otherwise, they keep their distance. If approached they are willing to talk and maybe even betray Noxidus if the party seems uninterested in the Shadowfell portal. They may offer the use of their signature magics in exchange for a vague "future favor" (the nature of which is left up to the DM.)
Tactics: The Algaetooth Sisters prefer to avoid combat where possible, but will fight to defend themselves. If combat breaks out, one of the hags immediately casts eyebite from their coven spell list, using the Panicked effect. One of the other hags upcasts a 5th level lightning bolt, while the last hag relies on her Death Glare action on any frightened creatures. If one of the hag's coven members dies, the other two lose their spellcasting and decide to flee.
This fight is an ideal time for Noxidus to launch an attack as well. The long straight hallway is a perfect location to use his breath weapon for maximum coverage.
7. Cistern
This round room is dominated by a raised cylindric cistern. The cistern is broken and pours cold water out to the west.
This cistern was connected to a pressurized aquifer and provided clean water to all of Grauvenbode. The explosion that destroyed the stronghold ruptured the cistern, causing the pressurized water to pour forth in an unending flood.
8. Hall of Statues
This chamber contains three statues of dwarven heroes, their names and deeds now lost to time.
Creatures: Two Chuul lay in wait beneath the water south of the room. The chuul are the servants of the Algaetooth Sisters and are under orders to waylay any intruders who approach the water. The chuul use their claw attack's automatic grapple to drag their enemies under water and towards the tunnel to Room 3.
9. Drowned Path
This passage is almost entirely flooded to a depth of 10 feet. The supernatural fog is thick here and the air chill.
Creatures: Three Vampiric Mist haunt this tunnel, indistinguishable from the fog that fills the dungeon. They gently drift up to the party as they travel down the passage, trying to leech away their blood.
10. Throne Room
This chamber is the ruined remains of a throne room. Its floor is flooded to a depth of 15 feet, the fog-shrouded ceiling rising a further 15 feet above the surface of the water. A raised balcony on the southern wall is now mere inches above the waterline. A stone throne rests on a slightly raised platform on the western end of the hall, entirely submerged. Around its base, beneath the water, there glitters a large hoard of gems, coins, and assorted treasures.
Treasure: Noxidus' hoard is composed of 10 onyx gems worth 50 GP each, 5 golden cups worth 100 GP each, the battle-axe of Faulthra Grauven which is worth 1,000 GP, as well as 700 CP, 5,200 SP, 1,700 GP, and 900 PP. Resting on top of them all is a headband of intellect and a suit of +1 splint armor.
Event: Noxidus' Fury: Provided the party hasn't slain Noxidus already, this room is an ideal location for the party's final clash against the shadow dragon. Noxidus will not suffer other creatures touching his hoard and will protect it with his life.
Noxidus waits until the party is well inside the room where they can't easily escape through Room 9 before striking. He starts the attack as an ambush, swooping in for a full melee multiattack against whichever enemy he considers the most dangerous before flying back out of range. He then says:
"Yes... This is what it feels like to feel. This thrill, this joy. Your company fills me. I will make you stay here forever."
Make sure to fight tactically, making good use of Noxidus' abilities that create magical darkness and his impressive movement speed. Refer back to the introduction for some specific tactics. In addition, try to save his breath weapon for when he can hit three players in a line; if that's impossible, always hit two. Don't hold back; this fight should be as brutal as possible.