Based on the real historical event of "privatization of water resources" in the 1700s, it tells the story of the struggle between the crown prince and the powerful forces that monopolize the water resources of the eight provinces of Joseon. It is a historical drama that combines political and romantic elements. Yoo Seung-ho will play the role of the crown prince Lee Hyun, who is righteous and courageous and fights against evil forces; Kim So-hyun plays the role of Han Ga-eun, a smart girl who seeks revenge on the crown prince for her father's death but falls in love with the crown prince unknowingly.