Yet another drama that I thought I would have zero interest in and it turned out to be a surprise hit for me. The premise didn't sound that interesting to me, but the amount of high ratings and reviews rolling in when it was complete convinced me to give it a shot. My non-Asian drama watching son even watched it with me and enjoyed it.
The story really kept me guessing for a long time and had a lot of suspense and thrills that raised my anxiety. I was hooked from the first episode, and was easily caught up in the unfolding of events that lead us up to the present day in the story. It was well-written and well-acted. What was surprising to me was how it was as much a love story as it was a crime drama. But it's not the new love kind of drama that you're probably used to as this is a couple that has been married for a long time. They know each other so well...or do they?
I think even people that aren't generally fans of mystery/crime might enjoy this and should give it a chance.

Believe it or not, this is the first time I've ever watched Lee Joon Gi, but his acting was superb. He played his character very well - watching the flickers of expression on his face (and there were many) as he experienced different emotions showed his remarkable skill. He could be cold and calculating one moment and loving and tender the next. Moon Chae Won had good chemistry with LJG and performed well also. I've not really watched her before either, but I enjoyed her in this a lot. I didn't have any expectations of the actors - maybe even low expectations - and I was blown away by how good they were.

I enjoyed the music in this also, and there were several really good tracks.