Veteran steel worker Gao Jin discovers a fatal crack in a load-bearing column during the rain, decisively stopping construction to save everyone, only to be unjustly accused by management of overstepping and fined five thousand. From then on, he starts strictly following procedures and leaving work on time. However, to rush the schedule, the project team covers up cracks, adds columns in violation of regulations, and replaces them with inferior steel, nearly causing a building collapse disaster. At the critical moment, Gao Jin, who was once mocked for minding other people's business, becomes the only person who can save the day. While stabilizing the danger, he produces layer upon layer of evidence to uncover the dark secrets, ultimately making everyone who ignored safety pay the price for their choices.