A fisherman named Dachuan finds an injured mermaid named A Lu by the seaside. Legend has it that a mermaid's tears can turn into pearls. He takes her home and coaxes her to cry every day, but A Lu's tears always turn into a puddle of clear water. Desperate to save his mother's life, Dachuan sells A Lu to Shopkeeper Zhou of the Pearl Pavilion. Locked in an underwater prison and chained in iron, A Lu is whipped whenever she cannot cry. Dachuan secretly visits her, overwhelmed by unbearable remorse. He risks his life to pry open the prison and escapes with A Lu toward a lighthouse by the sea. The night tide is about to arrive, and the pursuing boats are closing in behind them. At last, a tear falls from A Lu's eyes. Is this tear a farewell, or a new beginning?