Actually I don't like this movie very well, but I think this movie is excellent. In the first scene, movie starts with a video of surveillance camera in the Public Employment Security Office. Viewers cannot understand what that video means at that time. what viewers can see is the accident like murder happened in the office. But at the last, the meaning of the first scene becomes clear, and it connects to the story. The connection between the first scene and the last scene is excellent. The scene murder is happening is terrible, and the sound makes viewers scared.But viewers know the connection at the last, so it makes this movie refreshing and the refreshing feeling left inside viewers, not only horror elements.