Seven people wake up being confined in an autopsy room of an old closed ward. The protagonists who do not know why they are gathered at the closed room ask their own identities, threatening each other. Eventually, as a single event in which everyone is involved comes to light, the film shows the structure of the truth game of survival. Horrified people, the clock with mysterious numbers, the CCTV which seems to be watching over the characters and the like are settings which might have been inspired by Saw , the epitome of the secret-room horror genre. The flow in which the intersection of the flashback of the past and the present determines the relationship between characters is a singularity which diverges from the formula of the genre. This is not a familiar story of people cooperating in a mysterious situation; it is a bloody revenge play plotted by those bearing a grudge. The people amid this reveal their cheap nature of concealing one’s own fault and disclosing others’. This film conveys a Korean sentiment as it focuses on resentful feelings and the entangled stories behind the people.  The performance of actors such as Park Ha-na and Kim Young-min maximizes the beauty of this genre. Although they respond fastidiously or calmly under an extreme situation, they generally show madness. This is a piece of work from Director Park Gyu-taek who made a debut at 2014 with the horror thriller The Tunnel , which was set in a tunnel, or the secret room, as background. As he changed the background to a hospital, it induces an atmosphere which matches more with this genre compared to the previous work. (CHAE So-ra