This movie has to be one of the best,if not the best, mystery/psychologiac thriller in the history of movies, ALL MOVIES not only the Kdramas. There is too much to be told about this movie. At the start, I just thought that they had done something with his brother's brain, maybe someone took control of his body? maybe someone hypnotized him in doing this? But oh God it never came to mind how the whole thing was gonna end. The plot twists were unthinkable, I would never think of such a thing, the director has to be some kind of genius. And did I mention the actors' acting? God it was PERFECT! My boy Kang Ha Neul did such an amazing job ♡. The music? The way it made the suspense scenes even more suspenc-y; and scary was just amazing.

Truth to be told, I actually watched this movie bc of Kang Ha Neul (I love him sm) but I'm so glad I did. And Kim Mu Yeol, hello? His acting is perfect, I need more of him, please. ( Kang Ha Neul too, GIVE MY BOY MORE MAIN ROLES!!!)

Don't just put it in your watchlist to watch another time. Stop looking for more series/movies in this platform. Go watch it NOW! 1hr and 48mins is one and a half episode of a drama series, it won't hurt to go watch it now...
or...
maybe it will hurt in the end..?