Story: Thriller/Suspense. I personally loved how the story unfolded, and I appreciated that the PD left the audience to 'figure things out for themselves'.

Acting: The main cast did a stellar job. (Bias note: I totally loved Jang Ki Yong's dark tormented protrayal of thug Lee Gwang Il in 'My Mister', so I wasn't disappointed by his performance here whatsoever.)

Music: Where can I buy this OST!? I NEED it. One of the best soundtracks I've ever heard in a drama.

Rewatch Value: I rarely rewatch dark tragic dramas that don't have a happy endings (my gentle heart can't handle them). But I might make an exception for this someday in the future.

Overall: Worth watching if you're looking for a great thriller drama, and not expecting a romance.