Script-wise, I must say that it kept me on my toes the whole time.

Many plot twists and some moments when you could tell what's gonna happen next but no, you really couldn't! Very unpredictable!

It's one of those series that make you doubt and become more suspicious of everything. On the other hand, it's a drama that makes you feel compassion for the villain through the words of Inspector Koo and also by the villain's actions when something terrible happens in her life and she tries to cope with it later in the series.

I would say that Inspector Koo is a very strong woman who needs to keep herself busy all the time so she doesn't recall her past. During the series, we will see how she tries to cope with the loss of a loved one and how that has affected her whole being, not just her personality.

Moreover, while watching the series I felt torn by the killer's actions because a question was raised: Should we take matters into our own hands or let justice be served (before it's too late)? To clarify, I don't condone any criminal acts.

Last but not least, the cast's delivery was spot on.

Lee Young Ae and Kim Hye Joon played their roles perfectly and I liked the chemistry between them. I also liked the chemistry between Lee Young Ae and her team, Baek Sung Chul, and Kwak Sun Young.

Another thing that I enjoyed is the OST. The songs fit like a glove and they're very catchy too.

Overall, it is a great drama to watch and its rewatch value is high.