The Temple of the Drowned Voice

Overview

The temple is a pre-Sundering structure that predates Fort Valiance by millennia. It was built by a civilization that worshipped Zha'thaal — an entity from the deep places of the world that the Sarathi call the Drowned Voice. The temple's purpose was to contain and communicate with Zha'thaal, not to free it. Over the centuries, the seals have weakened, and Maren's crew inadvertently cracked the final seal by clearing debris from the altar chamber.

Read-aloud text:

The passage opens into a space that defies the cramped tunnels above. The ceiling soars thirty feet overhead, supported by columns carved to resemble tentacles rising from a stone floor inlaid with patterns of interlocking spirals. Everything is wet. Water runs down the walls in thin sheets, pooling in channels cut into the floor that all lead toward a raised platform at the far end of the chamber. On the platform sits an altar of black coral, and above it, the air shimmers as though you're looking at the world through deep water.

Temple Map

Room 1: The Spiral Hall

• •Entry chamber with the tentacle columns
• •Hazard: The spiral patterns on the floor are a glyph of warding (DC 14 to detect). Stepping on them triggers a burst of psychic energy: DC 13 Intelligence saving throw or take 2d6 psychic damage and hear whispers for 1 minute (disadvantage on Wisdom saving throws).
• •The whispers say things specific to each character — secrets, fears, half-truths designed to unsettle.

Room 2: The Drowning Chamber

• •A flooded room with water 3 feet deep
• •The far door can only be opened by turning two coral wheels on opposite walls simultaneously (requires coordination)
• •Encounter: 4 Giant Crabs (CR 1/8) lurk in the water, attacking when characters are waist-deep

Room 3: The Mural Room

• •Walls covered in faded mosaic murals depicting the pre-Sundering civilization
• •The murals show: a thriving coastal city, scholars communing with something in the deep, the construction of the temple, and finally — the sealing ritual
• •Key Information: A DC 13 Intelligence (History or Religion) check reveals the sealing ritual requires three components: salt, blood, and a spoken name. The salt and blood are obvious; the name is depicted as a glyph that a Sarathi character can read as "Zha'thaal."
• •Treasure: A spell scroll of protection from evil and good hidden behind a loose mosaic tile (DC 15 Perception to find)

Room 4: The Altar Chamber (Final Encounter)

Read-aloud text:

The altar chamber is wrong. The geometry doesn't quite work — corners that should be right angles curve slightly, the floor slopes in directions your eyes insist are flat. The black coral altar pulses with a faint bioluminescence, and the air above it ripples like the surface of a pool seen from below. And from that rippling space, you hear it: a voice that isn't a voice, a pressure behind your eyes that resolves into something almost like words.

The altar is the cracked seal. The shimmering above it is a thinning barrier between the material world and Zha'thaal's domain.

Final Encounter: Sealing the Breach

This is not a traditional boss fight. The goal is to repair the seal, not defeat Zha'thaal (which is far beyond the party's power).

Phase 1: The Guardian

The breach spawns a Water Weird (CR 3) that defends the altar. It rises from the altar's surface and attacks anyone who approaches.

Simultaneously: Tendrils of dark water reach from the breach, requiring characters near the altar to make DC 12 Strength saving throws at the start of each turn or be pulled 10 feet toward the altar and restrained until the end of their turn.

Phase 2: The Sealing Ritual

Once the Water Weird is defeated (or reduced to 0 HP), the breach begins to widen. The party has 5 rounds to perform the sealing ritual before the breach becomes permanent.

The ritual requires (discovered in the Mural Room):

1. •Salt poured on the altar (the stolen salt from the caves, or any salt)
2. •Blood — any character can voluntarily take 1d4 damage to contribute blood
3. •Speaking the name "Zha'thaal" three times (a DC 13 Charisma check; on failure, the character's voice catches and they must try again next round)

Each component takes an action to perform. With good coordination, the party can seal the breach in 2-3 rounds.

Phase 3: The Aftermath

When the seal is restored, the shimmer above the altar solidifies into dark glass. The whispers stop. The temple shudders, and dust falls from the ceiling.

If Maren is present and alive, the cessation of the whispers breaks Zha'thaal's hold on her. She collapses, weeping, and can be escorted out.

Conclusion

Rewards

• •XP: Completing the adventure awards enough XP for all characters to reach level 4
• •Gold: The recovered cargo can be returned to Dockmaster Ashwick for the promised payment (50 gp each, plus a 25 gp bonus for recovering the supplies)
• •Magic Items: +1 cutlass (from Maren), potion of water breathing, spell scroll of protection from evil and good
• •Story Rewards: Lieutenant Dorn is promoted to Harbor Watch Commander. She becomes a reliable ally for future adventures. Maren, if spared, can serve as a reformed NPC contact with knowledge of the Underdocks and the entity below.

Adventure Hooks for the Future

• •The seal is repaired but not permanent. The party now knows something ancient sleeps beneath Fort Valiance.
• •Maren's logbook contains evidence of corruption among Fort Valiance's noble houses — a thread that could lead to political intrigue at higher levels.
• •The Sarathi Enclave takes interest in the party after learning about the temple. They may offer training, information, or missions related to other pre-Sundering sites.
• •The sending stones could receive transmissions from other members of Maren's network who don't know she's been stopped.

DM Notes

• •If the party spares Maren, she makes an excellent recurring NPC — haunted by guilt, driven to atone, and uniquely knowledgeable about the threats beneath Fort Valiance.
• •The Drowned Voice is deliberately left mysterious. It could be an aboleth, a kraken, a vestage of a dead god, or something entirely unique to your campaign.
• •The Underdocks NPCs introduced in this adventure (Rellen, Nessa, Sera, Gutter Voss) form a ready-made network of contacts for future urban adventures.