Su Mai travels to the city to earn money for her father's surgery. She repeatedly hits dead ends while looking for work and eventually takes on heavy labor at a construction site. However, the contractor, Hu Qiang, withholds her wages. She never compromises her principles. By a stroke of luck, Su Mai's solid knowledge of civil engineering earns her the respect of Engineer Jiang, and she switches to quality inspection. She repeatedly uncovers substandard building materials, preserves complete evidence, and submits it to the regulatory authorities. She establishes her own construction team, recruits female migrant workers, and undertakes a school construction project. She works diligently and upholds her conscience.