On the night of its maiden flight, Lu Chen, an outsourced aircraft maintenance worker, suddenly orders a flagship passenger jet carrying 329 people to stop and accurately predicts that its hydraulic system will rupture. As an unmanned tug spirals out of control, flight data conflicts, and people become trapped in an old test-flight area, a series of anomalies all point to the XH417 disaster four years earlier that killed 11 people. Even more unsettling, deactivated access credentials, deleted accident records, and an investigation report written in advance are gradually pulling Lu Chen back to the center of the old case. As the Yunyi system interferes abnormally with multiple flights, he and Su Qinghe race against time to save aircraft in the air while uncovering the truth that has been concealed for four years.