In the early 20th century, Edith Cushing, an aspiring author haunted by her mother's ghost, encounters the charming but mysterious Sir Thomas Sharpe. Alongside his enigmatic sister, Lucille, Thomas appeals for investment in his invention from Edith's wealthy father, but is denied. Amidst growing suspicions and eerie occurrences, Edith falls in love with Thomas and, following a tragic event, marries him. Leaving her familiar surroundings, Edith relocates with Thomas to his dilapidated family mansion in England. The house, known for its blood-red clay that seeps through the walls, seems to possess a life and a darkness of its own.

As Edith adjusts to her new environment, she begins to uncover ghastly secrets hidden within the mansion. She experiences chilling visions and encounters spectral apparitions that appear to be warning her. The Sharpe siblings' intentions grow increasingly ambiguous, making Edith question their motives and her own safety. Battling both the supernatural and the very real dangers surrounding her, Edith's determination to unravel the mysteries of the mansion and its blood-soaked history intensifies, leading her down a dark and perilous path.