Supernatural suspense crime thriller. I was engaged from the first episode through the last. It's not easy to sustain the tension for 12 hours but the screenwriter, Kim Eun Hee, and directors do just that. The reveals build as we follow two parallel investigations - secular police detectives and a supernatural expert - separately pursuing the 'culprit' behind a series of suspicious suicides. These two avenues collide frequently as they bump into the each other following various evidence and leads. The performance of Kim Tae Ri as the focus of the story deserves praise as exceptionally well done. Her character is both the protagonist and the antagonist.