I’m disappointed. And annoyed.

The tense, the murder case, the characters, specially students in the school – were interesting and captivating. But solving the case, the detective work, the prosecutor work - were weak. The teachers keep finding clues by chance, without meticulous investigation, and there is no a strong turning point in the story or the moment of suspense. The pace is slow, I mean, the pace of investigation. Surprisingly the most coherent and fine parts of drama were school scenes with young actors.
The motive of temporary teacher (played by Yoon Gyun Sang) was important in the beginning, but later the writer didn’t have the concept of this any more. Unfortunately some of great and interesting characters in the drama were dead (I hope it isn’t a spoiler:) and protagonists who were alive – they were somehow flat. And I'm even not going to mention about the ending...
And my biggest problem with this crime drama: I feel the characters are created in a wrong way. Their actions don’t seem real. The psychology of characters is simple and unconvincing. And the actors acting is proportional to the script: average, average, average.
But the music was good.

So, there are some great scenes, with genius directing and filming (if you have seen the scene in the high-rise building, you know what I'm talking about), but it is not enough to enjoy this crime drama.