Laid-off quality inspector Chen Shuzhen sells starch sausages for two yuan each at the gate of County No. 3 Middle School, insisting on changing the oil every day, traceable raw materials, and never selling leftover grilled sausages overnight. Facing Gao Qiang, who steals business with low-priced, inferior goods, live-streams rumors, and frames her by impersonating "Chen's", she and her daughter Chen Xiaoman do not rely on shouting to prove themselves, but instead save purchase orders, raw videos, and delivery records, step by step piecing together the shady source supply chain. After the truth is uncovered, the mother and daughter not only protect their stall and reputation, but also make the open and transparent food safety rules truly stay.