Kkok Du was once a human male who lived in Korea’s past. The gods have turned him into an immortal grim reaper who must come to the mortal realm every 99 years to ruthlessly punish humans for their weakness and frailty. He has come to despise humans and is now cruel and pitiless. When he comes to the mortal realm this time around, he “possesses” the body of a promising young medic named Do Jin Woo. But he finds his mission to send souls to the afterlife compromised when he must fulfill Do Jin Woo’s medical duties. This leads him to cross paths with Han Gye Jeol, a doctor who graduated from the lowest-ranking medical school in South Korea. Despite her unpromising background, however, Kkok Du discovers that Han Gye Jeol has mysterious powers – and seems to have him under her spell. Could his fate have been intertwined with hers in a past life? Why does she have the ability to enthrall him so? Will he complete his mission – or could it be derailed by love?