The Sea Caves

Overview

The sea caves are a natural cave system carved into the cliffs beneath the Underdocks by centuries of tidal erosion. Maren's crew has expanded and reinforced the caves, creating a functional base of operations. The caves connect to the deeper tunnels that lead to the pre-Sundering temple.

Read-aloud text:

The cave mouth is a ragged arch of black rock, half-hidden by curtains of seaweed. Beyond it, the passage opens into a cathedral-like cavern where the sound of dripping water echoes from every surface. Makeshift walkways of salvaged planking span the tidal pools below, and oil lanterns hang from iron spikes driven into the rock. The air tastes of salt and something else — something older, like stone that's been wet for a thousand years.

Cave Map

The sea cave system has five major areas:

Area 1: The Sea Arch (Entry)

• •Accessible by rowboat at low tide
• •At high tide, the water rises to within 2 feet of the ceiling (Medium creatures must crouch, Small creatures can stand)
• •Two smugglers (use Bandit stat block) keep watch here

Area 2: The Supply Cache

• •A large cavern converted into a storeroom
• •Contains the stolen supplies: salt (20 barrels), rope (200 feet of coiled hemp), lantern oil (40 flasks), iron nails (6 kegs)
• •Also contains personal effects: hammocks, playing cards, a small shrine to the Sea Mother (desecrated)
• •Trap: The entrance has a tripwire (DC 13 to detect, DC 12 Dexterity save or take 1d6 bludgeoning from a falling barrel)

Area 3: The Tidal Pool

• •A natural cavern with a deep pool of seawater in the center
• •The pool connects to the open ocean through an underwater passage
• •Hazard: The pool contains a Giant Octopus (CR 1) that Maren has been feeding. It attacks anyone who enters the water or gets within 5 feet of the pool's edge.
• •Treasure: At the bottom of the pool (DC 14 Athletics to dive): a waterproof chest containing 75 gp, a potion of water breathing, and a silver pendant bearing the symbol of Zha'thaal (a spiral of teeth).

Area 4: Maren's Quarters

• •A private cave screened by a sailcloth curtain
• •Contains Maren's sea chest, navigation charts, and a journal
• •Maren's Journal: The final entries describe the temple's discovery and Maren's growing obsession. Key excerpt: "The voice is clearest at the altar. It knows my name. It knows everyone's name. It says the city above is just a skin — the real Fort Valiance is below, waiting to be reclaimed by the tide."
• •If Maren is present, she fights to defend the entrance to the temple (see below)

Area 5: The Descent

• •A narrow passage at the back of the caves that spirals downward
• •The walls transition from natural rock to carved stone — the pre-Sundering temple's upper level
• •Carved into the walls are Sarathi glyphs (DC 15 Intelligence/Arcana or a Sarathi character automatically): warnings to turn back, that what lies below "does not sleep but dreams"

Combat: Maren Blacktide

If the party has not dealt with Maren earlier, she confronts them at the entrance to the Descent.

Captain Maren Blacktide (use Bandit Captain stat block, CR 2, with the following modifications):

• •HP increased to 75 (due to Zha'thaal's blessing)
• •Whisper of the Deep (Recharge 5-6): As a bonus action, Maren whispers in a language she doesn't consciously know. Each creature within 15 feet must succeed on a DC 13 Wisdom saving throw or be frightened until the end of their next turn.
• •Tidal Shield: Maren has resistance to cold damage and can breathe underwater.

With her: 2 Thugs (CR 1/2) who are visibly terrified of the temple below but more terrified of Maren.

Roleplaying Maren: She's not a cackling villain. She genuinely believes Zha'thaal offers salvation — freedom from the corrupt nobility of Fort Valiance, power to protect the common people of the Underdocks. She'll try to recruit the party first. If a character makes a compelling argument (DC 18 Persuasion), she hesitates long enough for Gutter Voss (if present) to beg her to stop.

Treasure

• •Maren's sea chest: 120 gp, a +1 cutlass (use scimitar stats), navigational instruments worth 50 gp
• •The sending stone's partner (if the party has the first one from Chapter 3)
• •Maren's Harbor Watch logbook with evidence of noble corruption (useful for future adventures)