"The Diary of Ellen Rimbauer" follows the story of the twisted marriage of matriarch Ellen Rimbauer to the promiscuous early 20th-century industrialist, John Rimbauer, and the haunted beginnings of an enormous Seattle mansion that has come to life. Based on the best-selling novel by Ridley Pearson, passages of the diary track a series of deadly encounters surrounding the Rose Red Estate that transforms Ellen Rimbauer from the innocent and submissive wife of a wealthy industrialist into a woman possessed by the dark forces inhabiting her home.