Jiang Chaoshen, a young man from a fishing village, rescues Lanxi, an injured mermaid. The secret that mermaid tears turn into pearls is discovered by his greedy older brother and sister-in-law, who conspire with a dishonest merchant in an attempt to make a fortune from the pearls. Lanxi's captivity throws the bay's tides into chaos, fishing boats go missing, and the entire village ostracizes Jiang Chaoshen. Despite being misunderstood, Jiang Chaoshen repeatedly ventures into the sea to save her. With his uncle's help, he eventually discovers the secret passage where Lanxi is being held. When the great tide arrives, the truth comes to light, and the villagers work together to rescue Lanxi. The mermaid guides Jiang Chaoshen with silver fish, allowing him to rescue the missing crew members. After leaving behind a tidal conch and establishing rules to protect the sea, Lanxi returns to the ocean, and peace is restored to the fishing village.