In the series her singer mother homeschools her and they travel around the country by bus. In the series Fi's brother is skeptical of the occult. Their father was obsessed with it but died when Fi was only 3. Later on in the series Fi meets an entity called a will o' the wisp who seems to know her father and gives her information about him. He takes possession of her brother Jack's body in one episode until she expels him by discovering his name and saying it through a computer puzzle based on a hint he gives her. His name is Bricriu. Bricriu in a later episode takes possession of her mother's body and tries to prevent her from meeting a man who knows who killed her father. Bricriu lets slip to her that his allies in the spirit, although not Bricriu himself, murdered her father because of his investigations into their world. He finally meets Fi again in the first episode of season 3 and convinces her to give up interest in the occult in order to protect her family. Fi stopped appearing in the show after that episode. Fi met her father by time traveling to her third year in the episode Fountain. The first two seasons of the show, particularly the second, were dark. In the second season Fi even meets vampires. However, in the third season Disney decided to choose a lighter tone. Also Delizia left the show in the third season so she was replaced by Alex Johnson who played a new character called Annie who replaced Fi.