From the first episode, I enjoyed the story. The actions and sets are giving a Mission Impossible feel to it. The leads are doing such a great job, they're quickly established the characters and I got invested really fast. The acting is all just superb; Suzy did her best for her character, Go Hae Ri. Also, Moon Jung Hee was brilliant and intimidating, I love a good villainess. Of course, Lee Seung Gi was AMAZING as an Cha Dal Geun, he is an action hero! I was awed watching him running, jumping, chasing cars and did all those stunts. However, there was so much shaky-camera and it's so unfortunate because the camera was capturing really well-choreographed action sequence.

The twist and turns got a little bit too convoluted for me who is not a die hard fan of investigation and crime genres, but I never get bored as the plot is moving and stays high-stake all the way through the end. and yes, as most watchers have mentioned too, I don't like how it ended. Had that scene excluded, the drama would not leave such a frustrating after taste. Especially watching it after years it has aired and knowing there might never be a continuation to the story. That said, I don't regret watching it, one of the best in action genre.