Is the black hand behind "Obstinence Like a Shadow" the master?

Master

died in a car accident. After Gao Chuan was released from prison, he didn't believe that the master's death was a simple car accident. He wanted to find out the truth of the master's death. Gao Chuan could not accept the facts found, so what clues are there now?

First of all, on the day of Fei Zheng's death, witnesses saw that Fei Zheng did not die by suicide as the master said, but was forced to shoot to death by the master.

Secondly, Luo Song also checked the previous drug trafficking records from the anti-drug brigade, and found that the time for each multi-product transaction was during their mission. They helped Fei Zheng kill his colleagues every time, but every time they let Fei Zheng escape. At the same time, the pattern of drug dealing in the master's time has also changed, which makes people have to suspect that their master is the inner ghost.

Finally, what made Luo Song the most saddened and thought his master was a drug dealer was that the origami he gave to his master for Yun Haozhe was mixed with drugs.

According to the current plot, an investigation task force has been established to investigate the matter of Master Cheng Fenghua. What is the truth? Do you think the master is a drug dealer?