it is a good movie as in good acting and wasn't boring (interesting plot), but read comments saying her smile (at the end) indicated she knew everything and went along - total B.S. and wishful thinking.

Sung-yeol had planned the perfect murder and he would've gotten away with it, but he didn't foresee the dog being hooked-up with the spy-cam. that was his one and only downfall.

By the same token Ji-yeon lucked out cause of the spy-cam, otherwise history would've repeated itself and she would ended up paying for some other persons crimes. trying to paint her into some cunning vixen is B.S. - where she figure anything out? she didn't know he scouted her out, after finding any and all info about her, making sure she was desperate and all alone in this world. knowing there wouldn't be anyone she could turn to for help.
even if she suspected he was gonna kill his father (especially after him kissing her), she was sure he was into her, therefore he shortened his father life. so he could be with her, that's why she asked him if he had ever had feeling for her. after him trying to choke her out - she still care? and any one still wondering if she some master-mind? psssh plz.

btw the whole muslim yacht staffer who got beat, was a useless distraction. after witnessing them scheming together why he not suspect her? or Sung-yeol for that matter (him talking to him at the funeral, let alone getting in the car with him was idiotic) instead he was trying to get them the info about the spy-cam, how he sure she/or he didn't off Seok-goo?!? just cause she stepped-in when he was shoving/choking down pork? and cause he was the son - B.S.

back to the smile at the end, it was just a smile u give someone who is trying to have the last word. him saying he made her Cinderella, well so what? who is gonna spend years rotting in jail and who is gonna enjoy their freedom as well as all the wealth?!? his last words were a joke, so what would anyone do - but smile?