Southern Sea Cave
A tidal sea cave on the southern coast, mouth opening just beside where the great sea-beast washed ashore and rotted into bone. The cave only opens at low tide; at high water its entrance is swallowed by the surf.
The mouth was strung with a tripwire alarm — a fishing net staked taut across the entrance, lashed with cookware, bone, and the broken haft of a spear. The Tidefang's crew had rigged it to warn them of anything coming in from outside. It never sounded. Whatever came for them had not come from the sea.
Entrance pool. Past the mouth the floor slopes down to a shallow pool of trapped seawater. Giant crabs nest here, and at least one giant spider drops from threads on the ceiling. Past the pool, the Tidefang itself sits half-afloat in the shallows — a humble fishing vessel, sails frayed but mast standing — alongside the cold ashes of a long-abandoned camp.
The ship. Five neatly stacked bedrolls on the deck. A locked captain's quarters at the rear, holding a desk, an unlit lantern, and a logbook in Draconic. A door in the floor. Bookshelves with a waterproof scroll case and a charm necklace. Behind the boat, two cairns built against the cave wall — bedrolls smoothed flat under stacked stones, names scratched in charred Draconic on the rock above. No bodies; only names.
The deep chamber. Past the camp the cave narrows and opens into a chamber where all sound falls away. Bioluminescent moss casts the walls in shifting blues and greens; a wide pool of still black water reflects the glow like a dark mirror. Five lizardfolk lay dead here — four on the shore, one face-down in the water — bearing massive crushing injuries and pus-filled nodules. A chuul guarded the pool, a thrall of the aboleth.
The strange quiet in the chamber was not magical. Ribbons of a soft, oily, extraordinarily dense mineral threaded through the floor and walls — galena, rich in lead. The same shielding kept the aboleth's psychic call dulled here. A refuge that became a tomb.
The party recovered the Tidefang and its dead and sailed the old fishing vessel back along the coast to N.O.D.E. camp.