On a stormy night, an orphan named A Shi washes ashore in White Reef Village, clutching a conch shell. He is taken in by fisherman Gu Wenzhou. Strange sounds of the tide often emanate from the shell, leading to the secrets of a shipwreck from the past. Gu Wenzhou refuses to believe in supernatural explanations. Instead, he relies on tide records and on-site investigations to protect the local tidal creek ecosystem. Through storms, misunderstandings, and post-disaster reconstruction, the truth gradually comes to light. A Shi breaks free from the mysterious sounds that have bound him and finds a place to call home with the support of kind companions. At last, the sea returns to calm.