I just finished this and when I tell you this Drama is a masterpiece, I mean it.

The beginning was rather normal, for this show, at least. We thought we knew what was happening.
In the middle, I got confused as to why there were filler-like cases and was disappointed. Slowly, though, everything started to make sense. Everything was connected.
What we thought we understood in the beginning started having twists, things that weren't told showed up. It was as if they wabted to tell us the plot twist we thought we knew wasn't the main point of the show.
Literally EVERYTHING was connected, from the beginning to the end. And I think only geniuses can do this. Only geniuses can create such a masterpiece.