A violent gang that had clashed with the Serious Crime Unit 6 three years ago has resurfaced, but this time the new gang derived from it is even more brutal. Tao Fei (played by Wang Chao), who took office amid misunderstandings, temporarily became the acting leader of the Sixth Group. Ji Jie (played by Wang Qian), who had been transferred to the pre-trial department of the branch, also returned to the Sixth Group. Zheng Yimin (played by Zhang Chao), who was promoted to the deputy leader of the Criminal Investigation Detachment, and Yang Zhen (played by Ding Zhicheng), who now appears as the director of the Legal Affairs Department of the Branch - the new and old members of the Sixth Group collected evidence again. The criminal police defended justice, dignity, and honor at the cost of blood, cracked all kinds of serious cases, and finally wiped out this criminal gang, practicing the oath of the police with practical actions.