Maintenance technician Han Feng worked through the night to repair the factory's automotive welding line, saving the company 80 million yuan in losses. Yet the next day, supervisor Zhang Guodong fined him 6,000 yuan simply because he had removed his employee ID badge to fan himself during the repair. Disillusioned, Han Feng decides to follow the factory rules to the letter. When an imported production line suddenly breaks down three days later, he refuses to work overtime for free, forcing Zhang Guodong to apologize publicly and pay the additional expert fees. Han Feng then exposes Zhang Guodong's nephew, Zhang Bo, for sabotaging equipment and conspiring with outsiders. As a result, headquarters promotes Han Feng to factory director ahead of schedule. A year and a half later, Han Feng foils another plot by Zhang Bo and his accomplices, recently released from prison, to replace chips and blow up the production line. He leads the factory's transformation into the group's main base for new-energy vehicle welding and assembly, abolishes unreasonable factory rules, and establishes technical expertise and fairness as the factory's core principles.