IN SHORT:
It's an amazing humane drama with an incredibly beautiful narrative. The dialogues are so well versed they hit right into the heart! The quiet heartwarming background piano (sometimes violin mixed too) makes the past flashbacks scenes very alluring and majestic. Those first scenes (the flashbacks) are one of my top favorite bits of each episode!

The production was the definition of perfection till the drama's last breath! Kudos to Directors, Screenwriters, Composers and Actors, especially our beloved Moon Chae Won and LEE JOON GI. They did an outstanding job bringing the characters to life, Do Hyun Su's character was an especially hard one to pull, he truly deserves much love!

IN LENGTH:
The story takes it's time to develop the characters in the first few episodes, and the situation quickly escalates! You'll be surprised how much you're invested by the time the tragic strings of events begin!

The plot is about one man who wants to find the meaning of happiness for once, after dress rehearsing tragedy, in his entire life before! And a woman who wants such happiness for the man she is head over heels in love with!

After turning over his life, 18 years later in the present, he is pretty much what a perfect husband is expected to be! Doing too well to say! Everything is about to get ruined by a sudden turn of event that leads to uncovering his past! which seems to be filled up with misfortunes in more than one way!

The drama takes it's time to develop the main characters in present, while hinting about what could have happened in the past without giving too much spoiler early to fuel our adrenaline secretion, then suddenly we are thrown back to the past to only realize what actually is important is not what we were looking forward to the most! It's a whole different disheartening story that takes a creative take on self-inflicted misery, taking blame, and finding a middle ground for one's well being and happiness!

Acting is top notch! Lee Joon Gi as Baek Hee Seong is top notch! He looks totally dependable, manly and more than anything, a lovely dad! Whereas portraying Do Hyun Su couldn't be better executed! He looks so much younger now, and has a gaze that says the world about him, adorable and painfully cool in his yellow hair style!

Moon Chae Won is doing wonder with her acting! She has the kind of shaky, mellow voice that has emotions breathing out while she talks! She is an amazing actress who wonderfully fills the role of a very caring strong woman, Cha Ji Won, seeking happiness above all else for her family! She looks beautiful and mature, it's always great to see her again in a new drama!

I'm just gonna say! the music is just too perfect! From the incredibly suspenseful tracks "Flower of Evil" and "Switched Destiny" to the melo tracks "Upcoming Shadow" "Hard Relationship" to my most favorite track in this album "Cherry Blossom Kiss" which starts weird, mysterious and full of anxiety and emptiness, then it paces up to a sweeter tone then a more joyful and bright tone, which goes perfectly with Do Hyun Soo's character journey within the drama

We also have the feel nostalgic poetic piano track "Someone to Be Remembered" by Jung Se Rin (I noticed he has also composed the unbelievably beautiful track "When Mind Wants to Rest" from Naui Ahjussi)

There are only three songs on the entire album. (One of them "Psycho" by DOKO, being used only as an ending theme for the episodes and it's very catchy and goes well with the epic clifhangers.)

I have to say the remaining two are the most beautiful songs released in a drama this year! They aren't ever overused and it only plays when you really start to crave a song! They have that kinda impact!

"Feel You" by Shin Yong Jae is one of those two songs and it really deserves all the awards! Mark my words! An unexpressed love confession with lyrics beautifully wording out the feelings he has no idea sorting out for himself!
The melody is especially sad yet thrilling and makes our heart skipping beats! You can't tell what it exactly makes you feel, probably to reflect how Hyun Su can't distinguish between his own emotions, even in those moments his heart races like he is in pain!

"In My Heart" by LIM YEON is also a wonderful love poem, describing what Ji Won is feeling towards Hyun Su, and how even if her heart comes crashing down, she will face it, as long as it's love, she will be there, for her love!

I would probably re-watch this drama many times! It's that good. Tho the mystery element will be gone, it still has lots of suspense and drama to enjoy.

Highly recommended for fans of psychological thrillers and those who enjoy subtle romance plot-lines! A Must Watch Definitely.