Three years ago, the head of the criminal investigation team Cheng Wan personally caught the kidnapping convict Zhou Ye, but he did not expect that after he was released from prison three years later, he would become his daughter Xiaoman's class teacher. Cheng Wan carefully monitored Zhou Ye, only to find that he was not only patient and attentive to the children, but also helped Xiaoman solve crises many times. However, a kidnapping case similar to the old one happened again, and all the evidence pointed to Zhou Ye. However, Cheng Wan's mother Fang Zhilan saw in Zhou Ye the shadow of her son-in-law who disappeared many years ago. Cheng Wan must choose between family affection and justice, while Zhou Ye secretly investigates Sun Yao, the real mastermind behind the incident. From confrontation to cooperation, the two men jointly uncovered a truth that had been sealed for twenty years, but there was a darker deal behind the truth.
