In the turbulent autumn of the Republic of China, everything changed. Jiang Yuelou, the director of the Jingcheng Police Station, was both good and evil, which frightened the smuggling criminals. While investigating an opium case in Hong Kong, he met Chu Ran and Chen Yuzhi, and the three became friends. Chen Yuzhi discovered Jiang Yuelou's bipolar disorder. Jiang Yuelou refused treatment at first, but now he has a heart-to-heart with Chen Yuzhi. One kills, the other saves. The two people with diametrically opposed values redeem each other and become good friends who appreciate each other. In addition, the warlord Zhan Junbai, the Chamber of Commerce tycoon Zhao Jingming, the gangster Zhou Huo and others continue to make trouble and want to put Jiang Yuelou to death. The three good partners support each other and grow up in the process of counterattacks, and the secrets of the two families gradually surface during this period.