Three years ago, Chen Ye left Jiangcheng to join emergency rescue operations. On the day of his return, he found that his sister Chen Lan was being pressured to sign an accident settlement agreement. Chen Ye intervened strongly to rescue his sister, and discovered from an old iron box and a cracked mobile phone that his benefactor Zhou Zhengshan, who had saved him back then, did not die in a normal construction site accident. Chen Ye teamed up with Shen Qinghe, the head of Yuanhang Security, to investigate. Starting from candidly filmed videos, fabricated accident reports, and abnormal engineering accounts, they gradually locked onto Wei Donghai, Liang Zhen, and the mastermind behind the scenes, Gu Changchuan. Facing threats, blockades, and the destruction of evidence, Chen Ye relied on his superb skills to protect witnesses and rescue evidence, ultimately bringing the truth that had been sealed for many years back into the light.