Construction craftsman Chen Ting, while asking for unpaid wages, accidentally discovered that the contractor was swapping building materials with inferior ones, causing severe safety hazards in the affordable housing. Relying on his hard-earned craftsmanship honed over a decade and his sharp judgment of building structures, he successively exposed engineering dark secrets such as substandard steel and refurbished equipment. Facing industry suppression and pressure from the powerful, he never backed down. Assisted by independent inspector Lin Chuxue, and cooperating with regulatory departments, he investigated and punished the fraudsters according to law, safeguarding construction quality and the rights and interests of migrant workers. In the end, Chen Ting led his fellow workers to establish their own engineering team, winning back respect through their craftsmanship.