When deep-diving engineer Lin Xiang woke up, he found that he was a dock coolie at Quanzhou Port in the late Southern Song Dynasty. He had nothing but calluses. In the deep courtyard of Fanfang, the archaeologist Egret is trapped in the body of a mixed-race Arab girl. The theory of "voiceprint fossils" that she had been studying for twenty-two years was verified, but at the cost of being trapped in the era of her research object. The two of them could only convey a trace of warmth and direction to each other across the entire city. The energy has been depleted, and the only thing that can recharge the bracelet and return to the present day sinks to the bottom of the Ghost Reef. The sea there was calm but bubbling, and the fishing boats that went there never came back. The most powerful Pu family in Quanzhou is also secretly salvaging the same seabed. One has to learn to sail a boat from the bottom, and the other has to peek at the route from the cracks in the ledger. There are still nine years until the Yashan naval battle. They know better than anyone else the direction of this era and the outcome of the world's largest port. They are racing against time. Can they make it in time?
Intent: AD 1270, nine years before Yashan. Two people from modern times fell into this largest port in the East with the lowest status. Through their eyes, they saw again a real, rough, and about to be crushed Southern Song Dynasty. How would they deal with themselves and what would they do?