Xie Yu time-travels to Dajing, parachuting into Qingxi County to be a slacking, fish-touching county magistrate. He fears trouble and loves to lie flat, spending all day bantering and fish-touching with the earnest, inner-rolling registrar Su Qinghe, seemingly mediocre, incompetent, and perfunctory in his duties. In reality, his insight is astonishing and his logic top-notch, always when everyone is at their wits' end, cleverly solving bizarre folk cases based on minute flaws. Ordinary minor cases are connected layer by layer, entangling a wrongful case of a court military rebellion from ten years ago. The lazy salted-fish magistrate breaks the deadlock step by step, tearing off the hypocritical mask of powerful ministers, clearing away dark forces, and washing away grievances for the loyal and good.