The mermaid princess Lan tide went ashore to find her people who were captured by humans, and turned into a human being. She met the general Lu Zhao who was guarding the coast. Lu Zhao didn't believe in the mermaid legend, but was shocked when Lan tide used a fish tail to save a drowning soldier. He helped Lanxi find tribesmen, and Lanxi helped him fight against pirates. When Lan tide needs to return to the sea, the two of them have to face the distance between land and sea.
