Desperation drives two nuns to perform an exorcism no nun should attempt. With a possessed child at the mercy of evil and the opposition of the Catholic Church, they take on the dangerous forbidden rituals themselves, putting their immortal souls in grave danger. They must confront the terrifying cost of their sacrilegious actions, but one goal remains: the boy must be saved at all costs.

Hyun-soo, a C.E.O of a private detective agency, visits a pension with a client asking for her dog. While waiting outside of pension, he is falsely accused of kidnapping the client. During the arrest Hyun-soo, a serious car accident occurs and people misunderstand Hyun-soo as a prosecutor instead of a suspect. To find the real criminal, Hyun-soo pretends to be a prosecutor. Hwa-jin is an elite prosecutor but demoted to the provinces while trying to catch a law firm conglomerate Do-hoon, who colluded with the prosecutor’s leadership, meets Hyun-soo. Hwa-jin finds out the case is related to Do-hoon, she begins cooperating with Hyun-soo. While cooperating is on-going, they realize that there is a dirty truth behind the crime.

At 24, Hae-jin is caring for her mother, Jung-woon, who is in a coma—and finds herself wanting to run away dozens of times a day. One day, an aunt she has never met, Jung-hye, suddenly appears, holding an old childhood photo of Hae-jin. But Hae-jin remains wary of her. After moving her mother into a nursing facility, Hae-jin lives with a growing sense of guilt. Then, while cleaning out her mother's house one day, she finds the very same photo her aunt had shown her. That discovery leads her to the past Jung-woon once ran away from—and toward a new beginning of her own.