Diver Zhou Chao discovers hidden geological hazards in a mine shaft and issues repeated warnings. To take credit for the work, foreman Li Jianguo ignores him and forcibly proceeds with operations, ultimately causing a collapse that results in casualties. After the accident, the two team up with Boss Wang to frame Zhou Chao and even hire assassins to silence him. Armed with comprehensive evidence, including recordings and logs, Zhou Chao joins forces with witnesses to investigate the case layer by layer. He not only exposes the truth behind the accident but also uncovers an old case from ten years earlier. In the end, everyone involved is sentenced, and Zhou Chao devotes himself to protecting miners' safety and improving workplace safety regulations.