Late-60s/early 70s woman who works as a psychic medium in her own parlor; decades ago she worked for the enigmatic paranormal detective known as Earnest Salazar; she quit being a paranormal investigator when Salazar died; in the present day, Agatha has an uneasy relationship with his ghost, who continues his paranormal detective work from beyond the grave; Agatha is a mentor of the main character of the series, Juliet De La Cruz, a clairvoyant young woman; Agatha has recommended Juliet to be hired as Earnest's corporeal assistant -- with certain conditions.