Way in: by rowboat along sheer cliffs to a vine- and mangrove-choked sea cave. Inside it is deafening and stinks of brine and necrotic ozone.
What the party found, in order (S0–S1):
- The grate: about 50 ft in, a rusted, century-old iron grate (ripped out by Kintergas). Giant coconut crabs beyond it.
- The trapdoor room: up a ladder. Cave walls, one built stone wall, a 20-ft wooden ceiling, empty sconces. A huge iron-banded door with a magical drop-grate trap. Halfling-sized hole in the wall. Hidden door opened by a button under a cairn of rocks by the ladder.
- The gem room: a small dome studded with huge gems around a torch that never goes out. Touch a gem and you are teleported into a cell.
- The tower: a round stair tower with 3 skeleton guards.
- The cells (basement): four magical cells. Panels with keyholes appear when you press a hidden button; the keys hang on a hook. Contents: a tiefling corpse (with an Asmodeus Holy Symbol), a skeleton (with a coin pouch), and two empty cells, one bloodstained.
- The vault (middle landing): a spotless marble room with two lightning pillars (bridged with swords until they blew) guarded by 2 specters. In an iron-bound chest bolted to the floor: the phylactery cup.
The party died in the vault. Above them, the Harpers were besieging the place, and while Zaldara was dealing with the party they robbed her study.