This drama sees the human world from the perspective of death, with an increasingly suspenseful and misty plot. It tells the story of Black (Song Seung-heon), a Grim Reaper who guards death and possesses the body of a policeman, and Kang Ha-ram (Go Ara) who can see the shadows of death....

The drama tells the story of Ji-o (played by Kim Rae-won), who is sought after by the world because of his special abilities, and Goo-reum (played by Lee Da-hee) who is the only crime squad detective who remembers his appearance. They both fight against a huge conspiracy together. Based on Darwin's "On the Origin of Species", the seed of life that can be traced back to the origin of all life forms is called "LUCA"....