The warnings were all there but we chose not to listen.  In the end, corporate greed won out and our planet paid the price.  The polar ice caps melted, moving beach-front properties several hundred miles inland, and solar radiation microwaved anything left on land.  The brightest and wealthiest were able to escape to the Lunar Colonies and the Orbital Space Station.  The rest were forced below the surface.  Some burrowed ever deeper underground while the rest were taken in by the merfolk. That was 200 years ago. The Mariner Guild employs salvage teams to explore the ancient, sunken ruins from the old world in search of lost treasures and hunt dangerous creatures for resources and materials.  A curious young elf from the lunar colonies joins the crew of The Sea Nymph searching for the lost secrets of magic and adaptive evolution in hopes of reclaiming the surface.  The crew, however, are less enthused about having to babysit the researcher as they undertake dangerous missions in hopes of daily survival.