Former arms dealer Cobra discovers that every time he enters the Blue Hole, the ecology and terrain change, presenting a lucrative opportunity. He convinces the ever-optimistic Dave (the playable protagonist) and Bancho, a sushi chef specializing in rare sea creatures, to open a sushi restaurant nearby. While investigating the interior of the Blue Hole at the request of archaeologist Bacon, Dave finds that the descendants of ancient Sea People—who still live in the deep—are under threat. Realizing that this could be catastrophic not only for the hidden village but for the Earth itself, Dave dives deeper in search of a solution.