The drama features many themes and at first I was curious if they would be able to make me believe this world where ghosts exist. I was deeply immersed in the story and the world it built. The drama did a good job at establishing this world and had enough details and information to make the supernatural elements feel real and believable.

The mystery kept me on my edge till the end and the performances of the actors felt fitted to their roles. Kim Dong Wook proved himself as a good actor in other works before and his and the other's acting felt good and compelling. It's not easy to act something that doesn't have a real reference in life.
Those characters were humans with all their flaws and mistake and while one might judge some of their choices, this makes the characters feel more human in the end. The budding friendship and the bond of the three main characters was nice to watch and I'm so glad they drama stayed true to the characters by not forcing a conventional drama love line into it.

One of the reason that made this drama so good is also the music that contributed to the eery atmosphere and also gave a conflicted feeling of desperate and also hope at the same time. The songs were not overused and I never got tired of hearing them.

The drama was great and I would consider rewatching it in the future to let the story unfold in front of my eyes once again.