Kim Shin, a decorated military general from the Goryeo Dynasty, is betrayed by his jealous king and executed. He is cursed by the Almighty to live forever as a Goblin, watching his loved ones die while he remains immortal. The only way to end his eternal life is to find his destined bride, who must pull out the invisible sword embedded in his chest. After 900 years of solitude, he crosses paths with Ji Eun-tak, a cheerful high school student who possesses the unique ability to see ghosts and claims to be the Goblin's bride. As their fates intertwine, Kim Shin must navigate his growing feelings for Eun-tak while dealing with the Grim Reaper, an amnesiac entity tasked with escorting souls to the afterlife. The series explores themes of destiny, reincarnation, and the weight of immortality, as the characters uncover the tragic secrets of their past lives that connect them all in the present day.