You delved into a Latecomer ruin whose top sat just above the waters of a large, cold lake; each floor had to be sealed and drained, not having been an aquatic facility when it was built... Until you reached the seventh floor down, where merfolk had taken up residence - albino sealfolk and their pets, great blind otters that would sniff around the numerous stories below after the strange clams and oysters that lived in the effluvia-polluted deeps, growing pearls replete with arcane power. They were more than glad to trade with you for things of the world outside, where the sun would burn them if they tried to venture out.
