Kang Pil Sung (Song Sae Byeok) is a foul-mouthed but excellent detective. He is both lazy and rough and soft hearted. Hong Seo Jung (Koh Joon Hee) has excellent psychic mediumship, but she tries to hide her ability. In order to do that, she keep distance from other people and lives a lonely life. Possessed is about an absolute crime that interferes with the natural order of things by calling the soul of a serial killer executed 20 years ago, and by invoking the soul of a detective who initially catches a serial killer, to end the history of this crime.