The Captain's Last Order

You enter a circular cave chamber where warm seawater trickles down the walls and gathers in shallow pools around your boots. Tarnished brass plates gleam from the black stone, each engraved with a pirate symbol: a black flag, a parrot, a crescent moon, and a kraken. A faint sea-green glow pulses beneath the engravings. At the center, a coral-handled lever rests beside a dial whose pointer twitches whenever anyone approaches. Salt, wet rope, and old lamp oil scent the air, while something heavy shifts behind the sealed stone coffer at the rear of the chamber.