Chen Ye has been wandering around the old city for many years, hoping to find a big brother to back him up. However, he accidentally stumbles into a suspicious case at a flea market and is targeted by the police. He understands the rules of the street and recognizes the flaws in human relations, but he only knows a little bit about everything; the new policewoman Lin Wan understands the law and values evidence, but does not understand the routines of the market. One just wants to hide, and the other wants to find out. The two went from hating each other to being forced to work together, uncovering the truth behind the city in gray cases one after another. Chen Ye said that he only lived in the world, but every time someone was pushed into the mud, he couldn't help but stretch out his hand.
