I watched it because of Kim Sungkyu, because he is my favourite actor. So i was a little nervous about the movie, because i don't watch a lot serial killer "theme" movies. But it worth it! It was amazing! I loved how Ma Dongseok acted the badass gangster, it was really his role! Kim Muyeol was amazing too! But Kim Sungkyu, woooah dudeee, such a talented young man, (I mean he is 35 soooo nvm) i think the reason why they casted Sungkyu for Kyung Ho's role was that they wanted a hot villain you know lmao :') Anyways i rewatched it for six times and i enjoyed it always. If you like serial killers, gangsters, action or crime i can recommend it!