Drew by the heavy marketing, I have high expectation for this series. Watched until episode 13 and decided it is enough and gave up. Simple and predictable plot, but that is not the problem, simple plot can be sophisticated with good execution and presentation. Which is what this TV show lack. The director wants to produce an aura of suspense but the end product gives the feeling of incompleteness and leads to nowhere.
Characters have no depth and actually irritating and annoying. Dialogue cheesy and boring, at times, hilarious and illogical. It could be more bearable if actors are good. The lead actress - Yun-ah Song is a disaster, void of expression and 90% of time is stony faced. It is always a pain to watch bad lead actors and actresses because they dominated most of the screen time. The villain - Tae-Hwan Lee, overacting and just flat out bad acting. His translation of a bad person is to forcefully open his eyes as if in shock.
Personally I feel it is a waste of time and not recommended.