Unexplainable strange things began to appear in the city: the dead knocking on the door in the early morning, the last train with no end, and the previous resident appearing in the mirror. They do not come out of thin air, but come from past events that have been concealed, tampered with and forgotten. Audiovisual restorer Zhou Jiming discovered that if he wanted to survive the weirdness, he couldn't just follow the rules, but also investigate the source in depth so that the erased people could have their names back. Every time an echo ends, a relic will be left that can fight the next anomaly; every time it is used, hearing, organs, and even lifespan have to pay the bill. As the investigation deepens, he gradually approaches the truth about his father's early death, the mysterious Abnormal Events Bureau, and a "List of Non-Existences" that can make people and cases disappear from reality. And those who have been forgotten by the whole world are waiting for someone to hear their echo.
