Li Xiuying, a market vendor, sets up a public reweighing station to expose Liu Daqiang and other unscrupulous merchants for cheating customers with underweight goods. Instead, she faces pressure from fellow vendors to remove her scale. As disputes continue to plague the market, she quietly keeps a record of two years of weighing discrepancies. Then, she publicly purchases goods and reweighs them to gather evidence, using a certified scale to prove that her opponents have tampered with their weighing equipment. Eventually, the market establishes an official reweighing station and entrusts her with its management. With one small fair scale, she safeguards the precious justice that is so rarely found in everyday life.