There are many theories so far:

Q is the little girl Sinuo in the first film. Because Q is the initial letter of the English Queen, and Q uses God's perspective to examine all living beings, induce crimes, and kill people with borrowed knives. It is very similar to the method and character of Sinuo in the first film; and it is said that Zhang Zifeng will continue to star in the third film, and he is a mysterious and important character. The role of Qin can even give guidance to Qin Feng, who is ranked second, so she is likely to be Q.

Q is kiko. The first reason is the same as above, and the second point is the ending. Kiko says "immediately" implies "like you", and when kiko is combined, it is pronounced as Q. I was almost convinced by the second reason, but I also felt that kiko was unlikely to be Q. Because a "god" who is accustomed to hiding himself and using others to induce sin will disdain lying. He will react speciously, admitting but not giving evidence to others. Kiko clearly told Qin Feng that he had deciphered Q's ID and that he was neither in Canada nor the United States; and kiko's personality was very clear and his ranking was high. The number is so strong.

Q is Song Yi’s sister Song Qian. The first reason is the same as above, the second reason is Song Qian’s pinyin initials of “Qian”, and the third reason is that Song Qian is indeed not in the United States and Canada. But I personally feel that these reasons are a bit far-fetched, because I personally feel that Song Qian’s role in the play is only to induce Song Yi’s revenge. As a little girl who can be sold, her IQ may not be enough to control the overall situation. Of course, it is not ruled out that she deliberately made it look like she was being betrayed.

Q is Song Yi. First, Song Yi is obviously the top forensic doctor in the play. It is possible that the forensic crimes were induced by Song Yi, because as a Chinese teacher, Song Yi can see that he is very good at brainwashing others; second, if Song Yi Justice is Q, and the community message of the sugar factory in the play makes sense. But I personally think this is unlikely. Because Song Yi bluntly said "Q is my idol" and hinted at the end that she was not Q, kiko's statement also confirmed that Q is not in the United States (if she did not lie). Song Yi is most likely just a pawn of Q.

Q is Baoqiang. This hypothesis is the one I least agree with. Because there is "Q" in the actor's name, I think the character played by the actor is Q. This is really... And I think Tang Ren may be the most innocent character in the play, a little smart, a little wretched, and a little bit cunning. Sometimes I see clearly, sometimes I am confused, and I am mainly responsible for being funny.

Q is Qin Feng’s father. First, the initial letter of "Qin" is Q; second, Qin Feng's IQ is very high, and his father should be also good, and the person who can crush his son's IQ may be his father; third, Qin Feng's father once wanted to complete A perfect crime together, with a dark side in the heart; fourth, do you still remember Qin Feng’s shocked face in the second part when he saw the cloaked man take off his hood? Although the masked man was holding a scalpel, what he saw was definitely not the face of the forensic doctor, otherwise he would have solved the case long ago; it couldn't be Tang Ren, who appeared immediately behind; nor could it be Song Yi, Song Yi was busy changing the bodies, and if it was Song Yi that he saw, there would be no such long series of reasoning behind it. To sum up, this person is most likely someone Qin Feng knows, and has never thought of or wants to be exposed. Moreover, Qin Feng also squatted down and hugged his knees later. This kind of movement is usually a sign of vulnerability for children. It is very likely that Qin Feng's father has deceived Qin Feng all along - he has not gone to jail at all, or he has long been Escaped.

It is also said that Q is Qin Feng’s split personality. This... doesn't seem impossible. But in this case, the masked man mentioned in the previous article does not hold true. After all, personality can be split, but the physical body cannot be separated.

Most agree with the first and last hypothesis. My IQ is limited, so I can only analyze it here. Part of it is based on the analysis of the big guys.

Hope to adopt it, thank you!