I've already watched the 4th episode too and the scene where she opened that man's chest is nothing compared to what she did in the last episode!
I love strong female characters and I haven't seen Ha Ji Won in so long, so that was a bonus for me :) Though, there is quite a large age gap between the male characters and the female lead and I don't know how I feel about that.
I agree, the scenery is just so nice to look at!
Right now, I really enjoy the story and I'm intrigued by the characters' pasts and since the episodes are only 30 minutes long, I feel like I don't even have the time to get bored. I think they balanced quite smartly the 40 episodes into 30 minutes each because there are a lot of things that happen, but it still has a nice pace!
I'm looking forward to the rest of the episodes!