On his journey home after failing the imperial examination, the scholar Liu Yi encounters the Dragon Princess of Dongting Lake, who was married far away to Jingchuan. She has long suffered abuse from her husband and in-laws, living a life of misery. Moved by righteousness, Liu Yi bravely takes on the arduous task of delivering her letter to the underwater palace of Dongting Lake. Upon receiving the letter, her uncle, Lord Qiantang, launches a fierce rescue, and the Dragon Princess finally returns home. After many twists and turns, the two eventually become a couple.