Chen Mo, a graduate student in history, opens his eyes to find he has transmigrated into the body of a lowly archive clerk on the eve of Lin’an’s fall. The moment he wakes, he faces a dead end: the Yuan army is about to breach the city, and his head is about to roll. Fortunately, he carries a token bearing Lu Xiufu’s handwriting and a mysterious Kunning box. He crosses paths with Shen Yuan, an elite assassin who appears to be a musician at the Jiaofang Bureau but is actually a secret agent of the Song imperial house. Together with the surviving members of the Maritime Affairs Office, they escape certain death amid the Qiantang River’s raging tides, relying on Chen Mo’s modern geographical knowledge.
Lin’an has fallen, Yashan is in peril, and the cultural legacy of the Song is on the verge of extinction. With modern strategic thinking, chemical knowledge, and foresight into history, Chen Mo foils a traitor’s schemes, improves gunpowder, and seizes a massive oceangoing ship to establish a secret base on Deepsea Xinghuo Island. Shen Yuan wields her pipa as a blade, using musical codes and assassination skills to clear the way for him. From a doomed clerk to a ruler of the seas, from breaking out of Shepan Island to seizing ships at Quanzhou, from defending Xinghuo Island to eliminating a Yuan general, the two stand shoulder to shoulder as they gather the remaining sparks of the Song. They will make the ocean their domain and the sparks their torch, determined to defy the fate that “after Yashan, there was no Song,” and carve out a new maritime realm for the Song amid the chaos of war!