Lydia Carlton lives in Scotland in the nineteenth century, working as a fairy doctor. She is one of the few people who can see and interact with fairies. However, no one believes her. However, Edgar need someone who is well-versed in fairy lore, and Lydia is precisely that person. After saving her, he becomes her employer, but Edgar, who claims to be the Blue Knight's Earl, appears to be a man of many secrets and emotions.