Gu Su, a young archivist in the Lanjing Tide Trace Audit Department, is responsible for registering, identifying, and sealing historical fragments washed ashore in the Echo Sea. He does not believe in official documents - because official documents can be written for you; he only believes in the memory of personal experience - because the price is paid by memory. This belief comes from the back of his father who exchanged experience for skills, from the unknown person who put the bowl of rice on the street corner, and from his own birth record that has been written for him. He didn't know that his real name was Luo tide.
A name that should have been forgotten long ago cut through his peaceful archival career like a tide line. The name was engraved on a freshly landed tide mark, but the handwriting pointed to Lu Chen, the chief editor of the Audit Department who introduced him to the business. The deeper he pursued, the closer he came to a conclusion: Lu Chen was writing history, and even planned to dismantle the boundaries of the Echo Sea in order to awaken an "undocumented thing" that had never been witnessed.
He had to pursue him, not because he was brave, but because there was no way to retreat. Every time you use the retrospection technique, you have to pay for a personal experience; less than ten years before the big tide, the Echo Sea is losing its boundaries - if no one decides before the big tide which period of history will return and which period of history will be lost forever, the world will slip into an imbalance where multiple histories coexist.
When the truth finally unfolds, Gu Su will find that he is the pawn and anchor of the game. He must make the ultimate choice with his own hands: at the cost of all his memories, let a certain period of history come back and let another period sink forever. Some history must come back, some must sink forever—and the decision falls on his shoulders.
