Li Jianguo is a plumbing and electrical technician with 30 years of experience. Thanks to his exceptional skills, he discovers that a luxury mansion's renovation is being carried out with substandard materials and shoddy workmanship. However, the unscrupulous renovation director unjustly fires him. Upholding his professional integrity and the industry's standards, Li refuses to argue or seek revenge. Instead, he relies solely on his expertise to avert disasters in critical moments and protect residents' safety. With his real skills, he exposes fraudulent schemes and proves that honest craftsmanship and integrity are the strongest safeguards for every home.