People are really crapping on this film but to me, it was great. The acting is great and builds tension and the fact that the two main characters are deaf lets the movie use different ways of building suspense. An example would be the scene when the killer enters her house, and the noise activated lights start to blink, but the main character is turned away and doesn't see (of course). I also think it's great that those main characters DO get some justice in the end.

It's true that a lot of the other characters suffer from what is seemingly stupidity, but I think that more-so highlights their foolish dismissiveness of the daughter and mother's concerns due to their disability. They believe the killer isn't a threat simply because he's handsome and looks well put together. He acts a little bit like their caretaker in the police station and so they talk to him most of the time and give him respect he doesn't deserve. That justice aforementioned, therefore, has to be won by the main characters without any help due to everyone's unwillingness to understand until the very end. In addition to the anxiety built by the killer hunting them down, there's also added anxiety by a feeling of repeatedly reaching out and getting alienated to their situation in the process. It made me feel for the main characters and also want to cheer for them to succeed in the end. It also made me hate everyone else because their ignorance almost got the main characters, who WERE trying their best, killed. Very sad but horribly realistic picture of society in some situations in my opinion.

I also saw some comments saying the film portrays the main characters as "weak women" who can't do anything, but there's plenty of times that they had to fight for their lives - and win, especially the main character. The ending scenes really highlights this.

An argument could be made that the film is not realistic, but I think it's more of illustrating that fear of alienation, overwhelming knowledge of a horror others can't see, and endlessly running from that thing to others confusion. It also shows how that strength to overcome it sometimes has to come through yourself because everyone around you is metaphorically blind. It might not be Train to Busan or a five star k-drama, but for a 100 minute stand-alone chase thriller, it's great.

I love SK movies but this got more and more stupid as it went along. Could have been a lot better. Definitely wouldn't watch this again as with 45mins to go i just wanted to turn it off as it got dumber the longer it went on.

The main lead played by Ki-joo Jin is pretty solid..rarely you see such performance by actors playing deaf characters and evoking such emotions in the audiences...also the chemistry between Ki-joo Jin and the actor playing her mother....the plot has quite a loopholes...police is dumbed down a lot...killer always has the upper hand but ending is decent...