I'm so late in the game. Sorry, I know I should write a review when I'm done watching, But this drama is worth to get high rating even for just for the six episode I've watched. What make this drama is feels refreshing experience for me compare to any other show with similar premise. Heck, (I even rate this drama better than signal) for the fact this drama is meliticulously detail. I'm in awe of how structurally sound it's . What make it interesting each case is kind of related and can't be identified by face value. , the process of uncovering the truth is brutally realistic compare  to any regular korean drama procedural I've seen, that's why it take really long to get to the point. THe protagonist is a genius, IMO, but it doesn't give you the lisence to easily can judge human demeanor to commit a crime that easily, even with all clues pointing out to certain person, your judgement can be misleading. It's also interesting there is a possible alternative you also can become one of the culprit with all the evidence pointing out at you, can yourself also can be trust? Who is your friend? who is your enemy? Who is lying and who is telling the truth?   This kind of issue keep me glued to the screen. It's also allow us the viewers know more about our suspect and witness by digging them deeper.  The show is treat us as watchers  an intellegent viewers so they let us judge if what they are showing is what we get. And It's a plus in my book.