Han Ji-ri is from a goldmine island off the coast of Busan. A group of investors called the 'Roze Group' are aware of this fact, and wish to buy the island. To prevent this, Ji-ri strikes up a trade. She must locate the Sapphire Spinner, a rare fish with a sapphire lodged in its throat, in exchange for peace. Ji-ri seeks out a team, attracting disgruntled loan sharks, assassins and international competition. But Ji-ri has an ace up her sleeve to finding the Sapphire Spinner. With her body being almost ninety percent water, she has the strongest link to the sea her people know of.