The Criminal Police Team of the Municipal Bureau once received an audio file, which contained a recording of a call between M and Du Cheng before his death. In the recording, Du Cheng threatened to kill M to avenge Lei Yifei.With the help of Tongcheng Company, the surveillance video of the Whig Hotel on the night of the incident was enhanced for clarity, and Ducheng appeared in the video.Lu Haizhou handed these two pieces of evidence to his superiors, and Director Zhang decided to suspend Du Cheng temporarily.

Du Cheng, who was framed, took the initiative to hand over his work certificate. Director Zhang then announced at the meeting that Lu Haizhou would take over the case. Shen Yi questioned Lu Haizhou's purpose of coming to the Beijiang branch. Lu Haizhou told the truth and invited Shen Yi to the municipal bureau.At work, Shen Yi declined Lu Haizhou's invitation.

Shen Yi asked Du Cheng to tell him in detail his actions on the night of the crime. Then Shen Yi mapped out the scene on the night of the crime overnight, and told everyone what happened the next day.

On the night of the crime, Du Cheng came to the Whig Hotel and saw M falling when he went up to the fourth floor. He looked up and saw the murderer on the fifth floor.Du Cheng wanted to intercept the murderer from the fire corridor on the fourth floor. After the two fought, Du Cheng was kicked down the steps.Ducheng got up and chased after him, and the two fought fiercely on the second floor platform again. The camera should have been able to record the two people at that time, but the video sent to the police station only showed the blurred figure of Ducheng. This shows that the video was passedTampered.As a result of the fight between the two, Ducheng was pushed downstairs by the murderer, and the mirror of Ducheng's watch was damaged in the process.Du Cheng fell into a coma after landing, but when he woke up, he found that the murderer and the photo M gave him - the murderer of Lei Yifei - were the same person - Zhou Jun.

Shen Yi's analysis convinced everyone. No one believed that Du Cheng would kill M, so Lu Haizhou had to send Jiang Feng and others to control Zhou Jun first.

Lu Haizhou interrogated Ducheng, and Ducheng told Lu Haizhou a story.The man behind the scenes formed a human trafficking organization, but unexpectedly the policeman Lei Yifei caught the evidence, which forced the man behind the scenes to disband the organization. However, M, a key figure in the organization, rebelled at this time and took away important documents.The mastermind behind the scenes found M and discovered that M was in contact with policeman Du Cheng. In order to avoid further trouble, the mastermind behind the scenes sent Zhou Jun to kill M and put the blame on policeman Ducheng.

Lu Haizhou understood what Du Cheng meant, and then received the news of Zhou Jun's death. Before his death, Zhou Jun destroyed the important documents he obtained from M.After He Rongyue checked the computer, he found that Zhou Jun's death was caused by light-induced epilepsy. Shen Yi checked the files Li Han recovered from Zhou Jun's computer and found a virus file that could make the screen emit a specific flash.

According to M's description of Du Cheng, although she has not met the leader of the human trafficking organization, she has heard this voice before, and this voice recently appeared when Chen Zhou, the boss of Tongcheng Company, gave a speech.Zhou Jun's computer once contained photos of human trafficking, and his computer was also equipped with the Silver Eagle security system.Whig's surveillance is provided by Tongcheng Company with technical support, so only Tongcheng Company can tamper with the video. As a result, Tongcheng Company's Chen Zhou came into the police's sight.Because there was no search warrant, no one knew how to enter Tongcheng to investigate. Shen Yi proposed to force Chen Zhou to reveal his own flaws.

Du Qing brought Shen Yi to Tongcheng Company in the name of discussing cooperation. While Tongcheng boss Chen Zhou was away, the two carefully learned about Tongcheng Company's network security system. Shen Yi focused his attention on Chen Zhou's office.Shen Yi was carefully observing the fingerprint code lock at Chen Zhou's office door. At this time, Chen Zhou suddenly appeared. Fortunately, Du Qing came forward in time to help Shen Yi out.

Chen Zhou invited Du Qing and Shen Yi into the office to chat, and Shen Yi took the opportunity to extract Chen Zhou's fingerprints from the chess pieces.Chen Zhou offered to compete with Shen Yi on chess skills, and Du Qing left first.Chen Zhou's chess style was very aggressive. While playing chess, Shen Yi told Chen Zhou about the human trafficking case and the murders of Lei Yifei and M. Shen Yi's move was to stimulate Chen Zhou to take action.Only in this way can they find Chen Zhou's weakness.