Hunt for the Okeanus Scepter - Level 8 Adventure (Thalassia 2)

This article provides material to prepare and run an adventure titled, »Hunt for the Okeanus Scepter« as a stand-alone adventure, or as the second part of a mini-campaign set in the ocean world of Thalassia. The material below builds on the general setting information about Thalassia which you can find here: Thalassia Overview. Find the first part of the mini-campaign here.

The adventure is optimized for a party of four 8th-level characters.

Adventure Overview

Following the events at the Congregation, the characters might have allied themselves with a faction of Thalassia in the previous adventure. Whether or not you ran the first adventure, in this adventure, the party’s patron tasks them with recovering an artifact called the Okeanus Scepter from the ruins of Calathis, an ancient underwater city. The characters must navigate the treacherous Abyssal Depths, survive the threats of the ruins of Calathis, and finally retrieve the scepter.

The start of the adventure assumes the characters have already received the quest from their patron. (Let the players choose one of the factions of Thalassia as a patron if you did not run Intrigue at the Congregation.) In order to cut right to the action, we can handle the quest-giving »off-screen« before we begin the game. If you want, and you have the time, however, you can run a short interaction with the patron NPC in which the party receives the quest.

Strong Start

In the first scene, the characters are on an underwater vessel diving through a layer of the Abyssal Depths in their search for the ruins of Calathis.

When you’re ready to start the adventure read or paraphrase the following:

You dive deeper and deeper into the Abyssal Depths, with only the thin, shimmering force barrier protecting you and your ship. Through it, you can see seaweed the size of trees, and knots of kelp as large as boulders passing by the ship. You know the ruins of Calathis lie on the sea floor beneath these chaotic layers of the Depths.

While they are diving through this layer, called the Sunken Sargasso, invisible parasites called Balbazus have made it onto the ship, and are starting to feast on the characters. Roll initiative!

12 Balbazus are attacking the characters. They are invisible underwater, and the characters can only discern that they are being attacked at all after they succeed on a DC 11 Constitution save (see the Balbazu stat block for more information).

After the characters have dealt with the demons, they can continue on their harrowing journey through more chaotic layers of the Abyssal Depths.

Scenes

The goal of the characters is to find and recover the legendary Okeanus Scepter before another faction does. The following scenes might take place in the course of the adventure:

Surviving the journey through the Abyssal Depths to find the ruins of Calathis.
Finding the Okeanus Scepter in the Temple of Nereus in Calathis.
Return to the ship, and then to the surface, surviving an ambush from another faction.

Secrets of the Calathis

The following secrets, clues and bits of information can be revealed during the course of the adventure. You decide when and how to give these to the players — they might be disclosed by NPCs, deciphered in ancient carvings, or revealed through divine visions.

The faction or collection of factions the characters aligned with in the first adventure hire them to put the maps of Calathis to use. The maps reveal an artifact hidden in the ruins of Calathis, more specifically, in the Temple of Nereus — a place of worship for one of the Old Gods. The artifact’s name is the Okeanus Scepter and holds mysterious powers, described only as »creating currents« which travel across vast distances, connecting the most distant parts of Thalassia.
The Okeanus Scepter, lost artifact of the ancient Calathians, holds powers to open portals, access ancient memories, manipulate water purity, summon elemental forces, and create protective water shields. Its recovery could shift the political landscape of Thalassia, offering significant advantage to those who wield it or prevent its misuse. The fate of the depths and perhaps all of Thalassia could hinge on who controls this potent relic.
The lost people of Calathis worshipped a small pantheon of gods, now known as the Old Gods, and generally understood as a pagan, outdated, unenlightened religious belief by the Anglo-Fishian Church. At the head of the pantheon stood Nereus, son of of Okeanus, creator of the planet which was then called by the same name: Okeanus.
The maps show that Calathis lies hidden between the maddening layers of the recently discovered Abyssal Depths. The Depths are a maze of sequestered hellish ocean environments. Only a handful have been briefly explored, and many exploration missions never returned from a venture into the Depths.
The Abyssal Depths are crawling with a terrible variety of sea demons. Malignant, chaotic creations kept alive not by any natural adaptation but by constant destruction and iteration. It seems new layers appear, and with them new abominations crawl forth from the Depths.
Not much is known about the people of Calathis besides their pagan religion. Mainstream archaeology assumes the Calathians were a simple folk, living off the sea floor in simple conditions. A few fringe scholars, however, believe that Calathis was an advanced civilization, capable of feats that the general population of Thalassia could only dream of. These renegade researchers believe the Old Gods gave the Calathians powers beyond belief.
In truth, the Calathians were the first intelligent species to evolve on the sea floor, aeons ago. They built a prospering society, advanced cultural, religious and magical life. The Old Gods sometimes walked among the fey creatures that were the Calathians and helped them build their city, develop magic and prosper.
One day, however, an Old God by the name of Ghan An Bar deceived the Calathians. A war ensued between the Calathians and Ghan An Bar who could transform into a terrible dragon turtle. Ghan An Bar twisted the arcane magic suffusing Thalassia to create the Abyssal Depths and with them wipe out Calathis. It would take ten thousand years before civilization was built anew, separate from Calathis, by a different set of species.
The Okeanus Scepter was part of the creation of the Tree of Thalassia, the modern namesake of the planet. This tree stands on the Colony, and is the nexus of what is called the Anomaly — the source of arcane magic on Thalassia. The people of Thalassia only discovered it once they had evolved to survive on the surface. The discovery of arcane magic changed the fate of Thalassia forever and turned it into the industrial, scheming collection of city states it is today.
Todays amphibian Thalassians who make up the majority of the population are capable of living on land and water. But they are originally a sea-dwelling species. They knew divine magic before venturing to the surface, but thanks to the symbiotic evolution with a species of floating funghi, the Thalassians learned to survive above water. There, they discovered the Colony, and with it, arcane magic.
The Colony is a mostly inhospitable wasteland but the city states harvest stone, and more powerfully, wood charged with arcane energy here. These are the main sources of material for the construction of magical ships, and architecture and research in the city states of Thalassia. The land of the colony is covered in arcane radiation. Only the grung seem to have limited natural resistance to the radiation. Which is why they’re exploited by the ruling class to work on the the Colony.

Fantastic Locations

The following locations are settings for scenes during the adventure:

The Abyssal Depths: Overwhelming darkness, labyrinthine layers of chaotic ocean environments, abominable demons. These are some of the names of layers of the Depths. Use them to inspire the journey to the ruins of Calathis which lie on the sea floor beneath the Depths. You can roll a d10 or pick layers the party traverses on their journey to Calathis:
1. Iron Maw. A vast undersea canyon with walls of jagged metallic stone, patrolled by armored demonic sharks.
2. Sunken Sargasso. A tangled mass of supernaturally tough seaweed and kelp that ensnares the unwary, concealing predatory creatures within.
3. Brine Rift. A maze of salt-crystal formations that constantly shift and change, making navigation nearly impossible.
4. Abyssal Grotto. A series of underwater caves filled with luminescent fungi, strange echoes, and twisted, mind-bending paths.
5. Whirlpool Dominion. Dominated by powerful, demonic whirlpools that suck in everything, decorated with relics of sunken ships and the bones of sea monsters.
6. Infernal Reef. A coral reef heated by volcanic vents, home to fire-resistant demons and thermal vents that emit hallucinogenic gases.
7. Murkendraw. Dark, muddy waters where nothing is visible and movement is sluggish, inhabited by amorphous creatures that mimic the sea floor.
8. Cold Hell. Icy waters where the cold is so intense it burns, populated by ice wraiths and frozen undead.
9. Crushing Deep. Depths so extreme that the pressure threatens to implode any who dare venture too deep, guarded by creatures adapted to extreme pressure.
10. Nocturnal Sea. A layer of perpetual night, deeper than light can reach, home to sightless, luminescent predators and forgotten gods.
The Ruins of Calathis. Crumbling stone structures on the sea floor, roiling chaos of the Abyssal Depths above, ethereal whispers and songs, divine magic of the Old Gods.
The Temple of Nereus. Huge ziggurat; Use this map by dysonlogos; upper level with a shrine to Okeanus, ancient medical chambers, ground level with huge statue of Nereus and priests’ chambers, lower level with wards against Ghan An Bar, and the Okeanus Vault where the scepter lies.

NPCs

The group’s patron might send a representative with the party on their journey. In addition, a representative of a rival faction might ambush the party on their way back. Use the NPCs from the previous adventure, or generate new NPCs here.

Monsters

The following monsters can occupy any of the layers of the Abyssal Depths. They also function as guardians of the Temple of Nereus. You can roll a d10 to pick a monster randomly. The herald of darkness works as a final boss guardian of the scepter of Nereus.

Treasure

Use any treasure from the previous adventure which you have not handed out, in addition to any of the following:

99 sp, 3.360 gp, 110 pp (4.469gp), 250 gp aberrant gold hoops , 250 gp aberrant stylish silk doublet , 250 gp orcish fine tapestry , Potion of Greater Healing, Circlet of Blasting, Potion of Greater Healing, Potion of Greater Healing, Headband of Intellect
Okeanus Scepter. The scepter has the following abilities which become partially unlocked after this adventure. At your discretion more abilities become available in future adventures. These abilities are phrased as inspirational descriptions, choose appropriate mechanics:
- Dimensional Riptide: With a wave of the scepter, open short-lived portals to other water-based dimensions or locations across Thalassia, enabling rapid travel or escape
- Memory of the Ocean: The scepter holds the collective memories and knowledge of the Calathian civilization. The wielder can access these, providing invaluable wisdom and ancient secrets.
- Purification of Waters: The scepter can purify or toxify large bodies of water. This could be used to cleanse poisoned waters or alternatively, create barriers of uninhabitable water.
- Conjure Elemental Forms: Ability to conjure water elementals or storm entities that can fight, protect, or perform tasks at the wielder’s command.
- Shield of the Deep: Generate a powerful shield of pressurized water around the user, offering protection from physical attacks, pressure, and temperature extremes of the deep ocean, essential for deep-sea exploration.