Yes, this what I was looking for: mysterious, thrilling and new flavour into Korean movies.

It's a mix of everything, but be warned it is bloody! When the movie started they all ready had me sucked into it. I had questions, was intrigued by the format and loved it all the way.
Why? It had serious dark vibes, I love movies that make you think and wonder, questioning the main leads every move. the scenery was well done, the build up was even better, but I do think they lost some of it during a too long scene in the movie which was quite bloody.
I do find that they have picked very well fitted actors for the roles, nobody seemed too out of place and I loved Kim Da Mi and this movie might be a step up for more roles for her, she did great!
What also helped the movie was the well fitted music. It was building the tension immensely!

Watch this: if you like thriller/action movie with a dark tone and a twist here and there.
Skip this: Only if you don't like blood, if not, just give it a try.