Oh Soo Min is a spirited young Catholic priest affiliated with the 634 Regia, a group known for unofficial exorcisms. His mother's tragic possession and death left a lasting impact on him. Under the guidance of Priest Moon Ki Sun, the group's founder, Oh Soo Min learned the art of exorcism. Meanwhile, Ham Eun Ho, driven by a family tragedy, pursued a career in medicine and now works in the hospital's emergency room. Despite her lack of belief in God, a supernatural encounter and a meeting with Priest Oh Soo Min set her life on an unexpected course. (Source: MyDramaList)