Zhang Zhengshan, a retired senior engineer, is repeatedly begged for help by his nephew Zhang Lei to rescue a dangerous bridge built with substandard workmanship and materials. However, Zhang Lei withholds his consulting fees and maliciously smears his reputation. Recklessly using inferior construction materials, Zhang Lei causes an engineering accident and even attempts to substitute noncompliant materials for a cross-sea project, ultimately breaking the law. Zhang Zhengshan upholds the bottom line of engineering safety, takes over the cross-sea bridge project and successfully completes its final connection. He then establishes an engineering consulting company and helps his struggling nephew's wife, Li Mei, remaining true to the industry's founding principles and his own conscience.