Lu Dahai, an old fisherman from Beihai Bay, encounters danger while trying to save his family, but is rescued by a spirit turtle he once saved. This allows him to travel between the seas of the past and present to catch seafood. Repeatedly targeted and schemed against by the capitalist forces led by Tie Sha and Jiang Hong, he risks his life to save the poisoned spirit turtle and joins forces with Ye Zhen to gather evidence and thwart a land reclamation conspiracy. In the end, the villains are brought to justice, the fishing village develops its marine industries, the bay is protected, and everyone enjoys a happy ending.