This is a good crime drama with a well-written plot and characters. The overlap between characters flows nicely, so it does not feel forced. The pacing is also smooth and well-controlled, preventing the series from feeling slow or boring as the audience learns new things and sees developments in each episode. To me, this is an A series; I give it a 9.

I assume I'm not dropping spoilers since what I'm writing here is my guess, as this crime drama plays with a detective theme. To answer my headline question, I'm guessing the 'real' or the 'first' doctor is already dead. Now, who is playing the 'Doctor'? (whom I call the new Doctor). The new Doctor seems to care more about money above all, rather than maintaining control and power. It could be the prosecutor, the widow, the loyal secretary, or the narcotics chief.

While from enemy to friend story is cute and heartwarming, friend turning into an enemy is devastating. In this crime drama, I particularly enjoy the exploration of a friend becoming an enemy, as in this story, they were classmates in high school.

Lastly, Jae Kyung seems to be one step behind. Although it's a bit blurry, someone appears to be reading his moves. Let's see if the writer or director isn't too shy to push this narrative. I believe someone in the Narcotics Team is involved, my bet is on the lady boss. If it's not her, then the head of the Anhyeon Police Station might have something to do with it.

Final note: I understand that it takes a really smart writer to pull off a crime detective story where the culprit is someone close and well-known to everyone. It requires well-crafted settings to cover the tracks without flaws. Otherwise, it will result in plot holes. It would be safer if the writer used a side character, who the main lead is not very close to, as the main culprit.

So, let's see!!!