In Northeast China in 1983, down-on-his-luck young Wang Xiaoke seeks refuge with Fourth Master. Using his strategic brilliance, he brings order to the motorcade, chess club, and freight routes. Together with Su Xiaolin, he upholds their rules, while investigating old scores alongside Ma Long and Xiaofei, exposing the cargo-stealing schemes of Yang Mancang and his accomplices. Just as the crisis seems to have passed, Master Zhao, who disappeared eight years ago, brings clues about the mysterious Number Zero route. Danger is closing in step by step.