Twenty years ago in a small seaside village, Blake—a young psychic born into a Shaman clan—learns of an evil spirit called the ‘Guest’ that possesses weak people—driving them to go mad, kill their own families and stab themselves in the eye. During the harvest festival, Blake becomes terrorized by the Guest and his mother and grandmother gets killed overnight. Out of desperation, Blake becomes subjected to an exorcism by a rookie priest. Blake eventually heals but the rookie priest gets possessed by the Guest instead, killing his own father. Luckily, the priest’s younger brother, Matthew, manages to survive because a courageous female detective saves him, but she gets beaten to death. The police arrive and the detective’s young daughter, Lucy, becomes devastated after seeing her mother’s dead body. Blake and Matthew watch dazedly at the scene as they try to cope with their own horror of losing their families. The three children lose contact after that night but twenty years later, they cross paths again. Blake is now a taxi driver who uses his special gifts to help innocent people in trouble. Matthew is a Catholic priest, just like his brother, and hones himself to perform exorcism while suppressing haunting memories of the past. Lucy continues her mother's legacy by becoming a headstrong detective who does whatever it takes to help victims in need. The Guest returns and continues its brutal killings so the trio teams up to stop the evil force, once and for all. This is time, they will be ready for what’s to come.