it isn't mind blowing but if ur a crime & psychological junkie then i would recommend this. it is a longer movie but it wasn't excruciatingly dragged out. i definitely think there could've been more depth added within the plot (mainly the investigation) and i wasn't too big on the way the flashbacks were presented, idk it kinda felt messy. i think the characters are more of the focus but at the same time they feel slightly empty to me. don't get me wrong, i still enjoyed the movie, but it's definitely not the best thing i've ever seen. i'd say underrated in terms of average, nothing extraordinary. but a good watch if ur looking to numb ur mind and want to experience a thriller without it getting too complicated, yk? or there's the second option ... lee sun kyun ;)
