Empress Jiang Chenyu is feared by the emperor because her family has rendered great service to the throne, so she is exiled to Cold Reef Island. She leads the exiles in making use of local materials, relying on seafood, shells, peat, and other resources to improve their living conditions. Xie Wudu, commander of the Northern Sea Navy, forms an alliance with her, and together they discover that the deaths of Jiang Chenyu's father and brothers in battle years ago were caused by someone switching the military provisions. Despite repeated obstruction from the imperial court, Jiang Chenyu builds coastal defenses and modifies ships, using the advantages of sea routes to overcome crises. She exposes an old wrongful case, wins the people's support, and steadily expands her power. In the end, Jiang Chenyu leads her fleet to the capital and publicly clarifies the truth, ensuring that the mastermind receives the punishment he deserves. She establishes new rules in accordance with the people's wishes and ushers in a new era.