I watched this series because of Lee Bo Young and she is absolutely fantastic in her role of a grieving mother who's trying to save her young daughter from a seemingly predestined death in the hands of unknown kidnappers. We don't know why but she is given a second chance to save her daughter (and herself) by going back in time. The early episodes are excellent as we are thrilled by our heroine's courage followed by despair when it seems like every time the little girl is rescued, another hurdle came along, as though all roads lead to the same inescapable destiny.
Lee Bo Young is one of my favorite Korean actresses and her performance here is flawless. Her costar Cho Seung-woo is absolutely brilliant as well. He saved the show by his rebellious and so endearing character, what charisma this actor radiates even when he's playing a burnout depressive ex-cop! The little girl is so adorably cute that you just want the show to have more screen time with her, her mom and the ex-cop, instead of scenes after scenes of our leads running after one mysterious serial killer after another.
And that's my problem with this show. Without giving away main storyline or spoilers, it seems to me that the script writer equates thrill with the number of serial killers, other bad guys and riddles you can fit into a 16-episode series. How many times can a girl be kidnapped within a story? (More than in 24 season 1 for those who have watched that adrenaline-filled classic with Kiefer Sutherland). Instead of a coherent storyline and a fitting ending (whether it is happy or tragic) we're given a series of riddles and action scenes and an ending that made no sense in terms of providing a logical conclusion that is believable - even within the context of a supernatural thriller. Since this is fiction, I have no issue with the premise of a "second chance". What I am not able to accept is a pseudo-artistic ending where the characters behave in ways beyond any reason with an outcome that's not justified or explained in any manner.
I would rate the lead actors a 10 while the script and direction get a 4. So while I enjoyed the fantastic performance of the trio of actors, I can only commiserate with them to be letdown by such a miserable script which doesn't know how to tell and end a story, despite a very good start and concept.