To save 5,000 yuan on a third-party supervision fee, Chen Hang refuses professional oversight and decides to manage his new home's renovation himself using online guides. At first, he thinks he has everything under control and frequently boasts in group chats about how much money he is saving. But when the renovation nears completion, problems erupt all at once. The bathroom floods and smells of sewage, tiles have been swapped for inferior ones, the kitchen cabinets cannot be installed, and electrical junction boxes have been sealed shut. Every trade blames another, leaving the mess unresolved. Faced with one disaster after another, Chen Hang suffers serious delays and ends up spending over 20,000 yuan more on repairs and rework. With the help of supervisor Zhou Zheng, he finally gets the renovation disaster under control and learns a painful lesson: some money isn't really saved, because the value of professional oversight is irreplaceable.