Campaign Overview
In the bustling port city of Thalor, whispers of an Abyssal Cabal have begun to surface. Fishermen claim their captains have been replaced by fish-faced doppelgangers; merchants swear precious shipments vanish into thin water; and even the Maia Priests of the Tidal Mother speak of an ancient prophecy foretelling a cataclysmic flood. Few believe—until the coffer of the city’s harbormaster is found empty, its guardian dead by unknown claws.
As the party arrives seeking coin and excitement, what seems a silly conspiracy spirals into something far darker. Beneath Thalor’s docks lies a hidden network of coral tunnels where sahuagin hybrids thrash in mutation vats. Deep under rolling waves, a labyrinthine reef maze hums with bioluminescent energy and hides the torn remnants of a sunken temple. In these flooded halls, kraken sentinels lash out at intruders, and deceitful merfolk feign allegiance even as they plot undersea domination.
Guided by cryptic visions from the Tidal Oracle, the heroes must assemble the Seal of Coral—five scattered puzzle artifacts capable of opening or sealing a portal to the elemental Ocean Depths. Along the way they’ll:
• Navigate political intrigue in Thalor’s Council Chambers, where a doppelganger sits in place of a missing Overseer.
• Purify a poisoned Maia shrine beneath churning tides and claim the first Seal fragment.
• Delve into the glowing coral caverns of Delmaris, sabotage twisted mutation labs, and face off against a young kraken sentinel.
• Siege a blockade of Cabal warships and land on the drowned spires of Andros.
• Rescue captive Throneguard soldiers from grotesque vats and piece together the Cabal’s ritual blueprint.
• Confront Merfolk high priests, sahuagin champions, and, finally, High Priestess Maeralyth herself as she channels the ocean’s fury to drown the world.
Alongside the main quest, the party can: hunt mutated reef rats in the sewers, intercept smuggler convoys, uncover lost journals in wrecked watchtowers, and broker uneasy truces with sea-elf druids. They’ll wield tridents of coral, crush bioluminescent pearls for prophetic visions, and don scale mail forged from sahuagin armor. Each reward brings them closer to stopping the Final Flood, but each artifact also draws them deeper into maddening visions of the abyss.
Will they rally Thalor’s naval might and Maia’s faith to extinguish the Cabal’s ritual? Or will the tides rise, drowning the world and fulfilling the ancient prophecy? Dive into The Drowned Conspiracy of Thalor—a campaign of underwater exploration, political intrigue, and eldritch horror beneath the waves. Good luck, adventurers...and watch your gills for anyone who isn’t quite human.
Starting Location
Thalor Harbor District
Secrets
- A secret smuggler’s tunnel runs beneath the docks and ends in Spinefall Reef.
- The Guildmaster on the Council is already a fish-folk doppelganger.
- A hidden shrine under the Maia Temple holds the first piece of the Seal of Coral.
Key Locations
The Siren’s Prawn Tavern
Additional Notes
Council of Tides Chambers
Additional Notes
Rogues’ Reach Market
Additional Notes
Spinefall Reef Watchtower
Additional Notes
Maia Temple of the Tidal Mother
Additional Notes
Coral Labyrinth of Delmaris
Secrets
- An air pocket behind the mutation chamber springs open to reveal a side tunnel.
- The Oracle shrine’s altar can teleport purified visitors to hidden vaults.
- A hidden coral vault stores two pieces of the Seal of Coral puzzle.
Key Locations
Shrine of the Tidal Oracle
Additional Notes
Mutation Chamber
Additional Notes
Kraken Sentinel Nest
Additional Notes
Ruins of the Sunken City of Andros
Secrets
- A hidden chamber beneath the altar contains the Cabal’s leader’s identity and ultimate weakness.
- One pedestal is booby-trapped: removing the artifact releases a shockwave that knocks players back into flooding water.
- An air dome in the Hall of Echoing Depths has ancient scrolls revealing how to reverse the Final Flood.
Key Locations
Grand Temple of the Abyssal Cabal
Additional Notes
Council of Five Pedestals
Additional Notes
Hall of Echoing Depths
Additional Notes
NPCs in Thalor Harbor District
Admiral Calindra Lorenks
Other Details: Suspects something’s wrong in Thalor but lacks proof. Can commission players.
Marik “Two-Fingers” Claus
Other Details: Knows secret entrances to the Spinefall Reef caves; paranoid and may flee if spooked.
Priestess Serena of the Tidal Mother
Other Details: Wants the crypt beneath her temple purified and the artifact recovered.
Veshak O’Reen
Other Details: Can supply underwater breathing potions—for a stiff price.
Jasla Fynn
Other Details: Offers information on sahuagin sightings if her father’s fate is discovered.
NPCs in Coral Labyrinth of Delmaris
Pellara the Deepwarden
Other Details: May join the party if shown proof they fight for the reef’s health.
Captain Rendar Tuskbreaker
Other Details: If spared, can offer intel on the Cabal’s wider plans.
Sireness Melloria
Other Details: Will offer help, then betray them unless convinced otherwise.
NPCs in Ruins of the Sunken City of Andros
High Priestess Maeralyth
Other Details: Her scepter controls the bound kraken.
Brother Vallis
Other Details: If redeemed, can grant players a powerful blessing.
Captain Orna Stormsworn
Other Details: Defeating him yields the final Seal fragment.
Factions
The Abyssal Cabal
Goals
- Collect and reforge the Seal of Coral pieces
- Open the Final Flood Portal
- Transform the world into their aquatic domain
Relationships
With Other Factions
With Players
Throneguard of Thalor
Goals
- Uncover and root out corruption within the city’s leadership
- Assist explorers in confirming lingering coastal threats
- Rally undersea allies to counter the Cabal’s forces
Relationships
With Other Factions
With Players
Order of the Tidal Mother (Maia Priests)
Goals
- Purify defiled shrines and temples along the coast
- Form alliances with druids, sea-elves, and trustworthy merfolk
- Seal or destroy mutation labs to prevent sahuagin hybrid armies
Relationships
With Other Factions
With Players
Main Questline
Rumors in the Prawn
Given by:
Goals
• Follow the hidden tunnel under the docks
• Retrieve proof of fish-folk infiltration
Reward
- Map marking the tunnel beneath the docks
- 1 level Inspiration
Secrets
- The footprints lead to a mutation chamber used by the Cabal.
- A harbormaster’s journal is stolen by a fish-folk spy.
DM Notes
Crypt of the Coral Seal
Given by:
Goals
• Defeat the guardian water wraith
• Recover the Seal fragment and exit safely
Reward
- Blessing of the Tidal Mother (+1 AC for 1 hour)
- 200 gp
Secrets
- A hidden passage leads to mutated captives in an adjacent chamber.
- The crypt’s guardian spirit can be appeased for extra lore on the Cabal.
DM Notes
Into the Coral Labyrinth
Given by:
Goals
• Free the reefwardens and sabotage vats
• Defeat the Kraken Sentinel
• Collect two Seal fragments
Reward
- 2 potions of water breathing
- Pellara’s druidic boon
Secrets
- A hidden alcove holds a blueprint for the Final Flood ritual.
- Melloria intends to betray you at the maze’s heart.
DM Notes
Storm on Andros Shore
Given by:
Goals
• Land safely on Andros’s spire
• Clear a beachhead
Reward
- 300 gp
- +1 weapon forged by Throneguard smiths
Secrets
- One warship is crewed by fish-folk doppelgangers.
- Lorenks plans a diversionary attack that might end in friendly fire.
DM Notes
The Final Flood Ritual
Given by:
Goals
• Solve rotating coral puzzle amid battle
• Defeat Maeralyth and free or slay the kraken sentinel
• Reverse the ritual at the Deep Flood Glyph
Reward
- Titles and lands granted by Thalor
- Legendary magic item: Trident of the Tidal Mother
Secrets
- The Cabal’s true leader is a traitor in Thalor’s Council.
- The Seal’s final activation requires a willing sacrifice.
DM Notes
Side Quests in Thalor Harbor District
Lost Father of the Reef
Given by:
Goals
Reward
Secrets
- His map marks the entrance to a hidden mutation vat beneath a sunken ship.
- He was captured by the Abyssal Cabal and may now be a fish-folk pawn.
DM Notes
This quest introduces sahuagin combat and shows how deep the conspiracy goes. If the players find the vat, they learn of the Cabal’s mutation experiments.
Smuggler’s Toll
Given by:
Goals
Reward
Secrets
- The rival cell is fronted by a doppelganger posing as a dock overseer.
- Their buyer is a Merfolk emissary working for the Cabal.
DM Notes
Use stealth and social skill challenges. Players who discover the Merfolk emissary gain a direct lead to region two.
Coral Jewels Heist
Given by:
Goals
Reward
Secrets
- The arrowheads have faint runes tied to the Seal of Coral puzzle.
- The merchant convoy is under Cabal watch, protected by a kraken sentinel.
DM Notes
A timed mission with a chase scene on boats. A kraken guardian adds a formidable obstacle; scale HP for party level.
Pilfered Sermons
Given by:
Goals
Reward
Secrets
- The forgeries contain hidden invocations to awaken kraken sentinels.
- A temple acolyte is secretly working for the Abyssal Cabal.
DM Notes
This quest lays groundwork for the Cabal’s ritual intent and introduces kraken sentinels as guardians.
Harbor Rat Extermination
Given by:
Goals
Reward
Secrets
- A rat queen in the sewers has been injected with sahuagin blood.
- The vermin infestation was engineered to distract guards from Cabal activity.
DM Notes
A low-level combat to give players confidence, but mutated “water rats” hint at the deeper plot.Side Quests in Coral Labyrinth of Delmaris
Rescue the Reefwardens
Given by:
Goals
Reward
Secrets
- The sailors chained there include a Throneguard sentry with vital logs.
- One druid is already halfway mutated; sparing them could yield unique knowledge.
DM Notes
A stealth/combat hybrid. Players must disable wards (Arcana DC 15) before chains can be broke.
Recover the Kraken Eye
Given by:
Goals
Reward
Secrets
- The Eye is held in a locked chest guarded by sahuagin spellcasters.
- It’s trapped: removing it unleashes a shockwave that floods nearby corridors.
DM Notes
Encourage creative disarming—players might use water spells or brute force.Side Quests in Ruins of the Sunken City of Andros
Save the Throneguard Expedition
Given by:
Goals
Reward
Secrets
- One survivor has the final Seal fragment implanted inside them.
- Their memories contain crucial details for stopping the ritual.
DM Notes
A high-risk stealth and combat mix. Vats activate in waves—fighting off mutated abominations.
Reverse the Deep Flood Glyph
Given by:
Goals
Reward
Secrets
- Activating late partially undoes the ritual, causing unpredictable elemental storms.
- The glyph draws on the user’s life force—one hero must remain behind.
DM Notes
A puzzle/skill challenge. Each mistake causes water surges (each character takes 2d6 bludgeoning).Encounters
Sahuagin Ambush at Low Tide
Medium
Suggested Level: 3–5
Creatures
- 4 Sahuagin Warriors
- 2 Sahuagin Spellcasters
Terrain Features
- Tidal pools (DC 12 Acrobatics or fall prone)
Treasure
DM Notes
Mutated Reef Rats
Easy
Suggested Level: 2–4
Creatures
- 6 Mutated Sewer Rats (use Giant Rats stats, +1d4 poison damage)
Terrain Features
- Puddles of toxic sludge (Con save DC 10 or take 1d6 poison)
Treasure
DM Notes
Kraken Sentinel’s Guard Duty
Hard
Suggested Level: 6–8
Creatures
- One Young Kraken (scaled)
Terrain Features
- Ink clouds (Dex save DC 14 or blinded)
Treasure
DM Notes
Merfolk Deception
Medium
Suggested Level: 4–6
Creatures
- 3 Merfolk Envoys (use Noble stats)
- 2 Merfolk Tridentiers
Terrain Features
- Concealed rock outcrops (cover)
Treasure
DM Notes
Haunted Crypt Spirits
Deadly
Suggested Level: 7–9
Creatures
- 2 Water Wraiths
- 4 Spectres
Terrain Features
- Echoing corridors (disadvantage on Stealth)
Treasure
DM Notes
Magic Items
Pearl of Deep Visions
Rare
Location
Attunement
Trident of the Tidal Mother
Legendary
Location
Attunement
Coral-Bound Amulet
Uncommon
Location
Attunement
Ink-Soaked Pearls
Common
Location
Attunement
Rat Queen’s Talisman
Uncommon
Location
Attunement
Sahuagin Scale Mail
Rare
Location
Attunement
Crystal Diver’s Spyglass
Uncommon
Location
Attunement
Potion of Ocean’s Might
Uncommon
Location
Attunement
Merfolk Emissary’s Trident
Uncommon
Location
Attunement
Bioluminescent Coral Shard
Common
Location
Attunement
Player Characters
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