A D20 fantasy RPG, Tales of Argosa combines fantasy with sword and sorcery, leavened with a touch of horror. The mythical Serpentmen city of Koth-Zagash from an adventure using that ruleset is rumored to have been swallowed by rising seas during the Second Age. A lost artifact is there that PCs may want. A perfect time to use the D20 version of the adventure Dead in the Water from H. P. Lovecraft’s Kingsport.

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This adventure promises fog-shrouded urban brawls, nautical combat, undersea exploration and dangers, and a face off against an otherworldly horror backed up by a haunted ship of undead led by a piranha man! The PCs will have their hands full and their minds endangered.
Kingsport in The Midlands
A setting book for Tales of Argosa,The Midlands Low Magic Sandbox Setting has a lake to hold the drowned location and a settlement called Port Brax. I plan to replace that city with Kingsport, and have just a portion of the underwater ruins guarded by the alien Starmother.
While Kingsport is designed for 1920s New England, at its heart, it is a port city with fishermen. Modern or medieval doesn’t really matter. A few tweaks to remove tech, and the city will be adventure-ready.
Gangsters attack the PCs in Dead in the Water. These thugs can be replaced with humans from page 187 of Tales of Argosa: four archers and four bandits led by a human berserker with 3 HD.
If the bandits are defeated, the locals will assist the PCs. They will let them borrow a boat with a diving bell to sail out to the drowned city and go diving. While the area is supposed to have a small unit of marines stationed there, the post has been empty due to the southern wars, which also explains why the bandits grew so bold as to start exhorting inside the town itself. The marine’s cog is still available however, and a few brave fishermen are willing to serve as crew. They warn they PCs that the fog shrouded part of the lake they want to sail to is haunted.
Dead in the Water: Naval Combat
Tales of Argosa has rules for naval combat. The Starmother can raise a ship from the bottom of the lake which is crewed by undead. This combat can be run using the normal rules treating both ships as cogs with a ballista (ToA p. 208). The undead crew includes eight skeletons armed with multiple spears for throwing and thrusting led by a merscine (piranha man ToA p. 191). On a natural 19, a giant crocodile with a ticking clock inside comes to assist (ToA p. 176). The clock can be retrieved: when checking for initiative also roll a d12, on a 12 a failed roll becomes a success and a success a great success. A great success allows the next person rolling for initiative to roll with a d12 with the same possible results.
Dead in the Water: The Starmother
Two options are provided: a weak outsider or demigod. Demigod seems a bit much, so large outsider it is.
The Starmother
The Starmother is a chunk of yellow-green stone about the size of a cat. It is shaped like Ursula from the Little Mermaid: top half of a woman and bottom half octopus. From the stone extend dozens of strands. These strands can attack, direct detached tentacles in battle, and can lower and drown the cog the Starmother uses to defend her lair where the item the PCs want is hidden.
Starmother
Level 12Flailing Cilia. 4d6 damage against up to four attackers.
Alien Vision (19). Mind blast 6 damage and Luck (WP). Failure: 6 more damage and stunned 1 round and one Independent Tentacle gets free attack.
2-8 Murderous | 9-10 Ravenous | 11-12 Destructive
Independent Tentacles
Level 2Flailing Tentacle. 1d6 damage.
Alien Vision (19). Mind blast 3 damage and Luck (WP). Failure: 3 more damage and one Independent Tentacle gets free attack.
Dead in the Water: Diving for Treasure
PCs who defeat the Starmother will find an ancient temple at the bottom of the lake. It matches the description of the ruin they are looking for. They just need to descend via diving bell or water breathing to claim their treasure. Lurking in the water are 1d2+2 chuul. If the PCs are attacked in the diving bell, on a natural 19 a chuul cuts the chain connecting the PCs to the surface.
Once to the ruins, the PCs will need to complete a skill montage to get inside and find the treasure (ToA p. 85). Setbacks include falling debris, a pack of piranha, a damaged lock to doors hiding the treasure, spear spikes, and other delays and dangers as the GM sees fit.
Falling Debris
Part of the ruin gives way and comes crashing down. The PC needs to avoid getting hurt and pinned.
Luck (Dex) save to avoid 1d6 damage and becoming Prone and Grabbed until dug out using Strength.
Pack of Piranha
Roving pack of carnivores looking for a PC to nibble on.
As Rat Swarm with Swim. Tales of Argosa page 172.
Damaged Lock
Jammed shut. Can be finessed open (Dexterity) or broken open (Strength).
Spear Spikes
An ancient defense, still potent.
Tales of Argosa page 227.
Next Steps
Once the PCs defeat the Starmother and complete the dive to retrieve their treasure, they will likely return to Kingsport to return the cog. If they don’t, they could always steal the cog and become pirates. Otherwise, the city hails them as heroes. Future adventures could easily spin out of this settlement as the PCs continue to explore the haunted fog-shrouded city and surrounding shore and wilds. H. P. Lovecraft's Kingsport offers additional adventures, as does The Midlands Low Magic Sandbox Setting.
Picture credit: Pixabay
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