Chen Mo, a graduate student in history, opened his eyes and traveled through time to become a humble archives clerk on the eve of the fall of Lin'an. When he woke up, he was faced with the fate of the Yuan army breaking the city and killing everyone. Fortunately, he was carrying Lu Xiufu's autographed keepsake and the mysterious Kunning Box. He encountered Shen Yuan, a top assassin who appeared to be a Jiaofang Sileji but was actually a secret sentry for the Song Dynasty royal family. Together with the remnants of the Sea Road Division, the two of them managed to survive the tide of the Qiantang River using modern geographical knowledge.
Lin'an has been broken, Yashan is in danger, and the cultural context of the Song Dynasty is on the verge of being cut off. Chen Mo used modern strategic thinking, chemical knowledge and historical prophets to defeat the traitor's plot, improve gunpowder, seize the ocean-going giant ship, and establish a secret base on the deep-sea Spark Island; Shen Yuan used the pipa as a blade, relying on musical codes and assassination skills to clear the thorny path ahead for him. From a petty official waiting to be killed to the overlord of the sea, from breaking out of Shepan Island to seizing ships in Quanzhou, from defending Xinghuo Island to sniping Yuan generals, the two worked side by side to gather the remaining fire of the Song Dynasty, using the sea as their frontier and the sparks as their torch, vowing to break the fate of "there is no Song Dynasty after the cliff mountain" and open up a new maritime world for the Song Dynasty in troubled times!
