Crimson Peak In Buffalo, New York, 1887, American heiress Edith Cushing is the daughter of a wealthy businessman Carter Cushing. In the night the young Edith is visited by her deceased mother’s black, disfigured ghost who warns her “Beware of Crimson Peak.”
In the year 1901, Edith, now a budding author meets Sir Thomas Sharpe, an English baronet, and his sister, Lucille. He seeks investors for his invention, a digging machine which he hopes will bring back the defunct clay mines of the estate of his family. Sharpe’s proposal and his failures when it came to raising capital earlier have left Mr. Cushing unimpressed and he is averse to the idea. But, Thomas charms an initially difficult Edith, and the two become romantically attached. Thomas asks that Lucille gift him her ring, which is a family heirloom, which she passes over, stating that she is expecting it to be returned to her.
Cushing has a personal dislike of the Sharpes and employs a private detective, Mr. Holly. Holly uncovers a number of unsavory details concerning the siblings. They are then coerced by Mr. Cushing to leave America. He also insists that Thomas “break Edith’s heart” and leads Thomas to disparage Edith’s novel. The next day, Thomas returns Edith’s manuscript along with a letter outlining his actions. Edith accepts Thomas’s offer and the couple eventually reconcile. The next day that day, Thomas. Cushing is brutally murdered at his club. Edith declines Dr. Alan McMichael’s suggestion to investigate the matter further.
Following the funeral, Edith gets married to Thomas and they depart for England. They land at Allerdale Hall in Cumberland. The Sharpes’ crumbling mansion is sinking slowly into the Red Clay mine that it sits on top of. It is also constantly being destroyed by the elements. Lucille is cold with Edith and Thomas, while Thomas is distant physically and their marriage is not a disaster. Lucille constantly slats Edith with tea made of “firethorn berries” and Thomas convinces her to purchase the first half of her father’s estate so that she can continue work on his mining equipment. The winter months are approaching and Thomas states the estate is referred to as “Crimson Peak” because of the warm red clay seeping through the snow. The siblings discuss the way their father was brutal and squandered the fortune of their family while their mother was harsh and distant.
Edith gets weaker and begins coughing up blood. Edith has a series of frightening nightmares. She has visions of the ghosts of skeletal, red skeletons in Allerdale. It tricks her into opening a closet where she discovers wax phonograph cylinders and then chases her into the cellars, where she finds a locked trunk with “Enola” engraved on the latch.
Thomas takes Edith with him to the local postal office. There, the clerk hands Edith an email from Italy addressed to E. Sharpe. Thomas and Edith are stranded inside for the night and take the chance to finally fall in their love. Lucille is furious with Edith who isn’t sleeping with Thomas when they return. Crimson Peak HD
One of the keys Lucille is carrying bears the name “Enola” and when Lucille is lost, Edith steals it. Edith uses it to open the trunk of the cellar. Edith then finds the gramophone she can utilize to play the wax cylinders inside the closet. Between these and the letter from the post office she finds out that Thomas was previously married to three wealthy women. One of them was an Italian known as Enola Sciotti. Edith discovers that Lucille has poisoned Edith and that her siblings are involved in “marriage-and-murder” strategies to fund themselves as well as finance Thomas’ inventions. Edith confronts her brother and wife in law, however Lucille is able to catch them in a passionate embrace. Lucille is pushed by Edith off a balcony to try and take her life however she breaks her leg.
Meanwhile, back in the United States, Alan has discovered the information Mr. Cushing uncovered about the Sharpes before his death Thomas’s numerous marriages and Lucille’s stint in a mental institution. He travels to Allerdale Hall in the dead of winter to save Edith. When Alan arrives, he finds Edith wounded, but when he wants to take Edith back to her village Lucille refuses. Thomas is in the love of Edith and feels trapped by Lucille. He wants to get rid of her. Lucille is stabbed by Alan in the underarm and insists that Thomas finish the job. To protect Edith, Thomas inflicts an accidental, but not fatal stabbing wound to the stomach of Alan. Then, he hides him. Lucille obliges Edith to accept a transfer deed giving the Sharpes ownership of her estate, and admits to killing Thomas his previous wives. She also admits to having been pregnant with Thomas but that it passed away soon after the birth. Edith’s father was also murdered by Edith’s mother. Edith’s father was also found having a sexual relationship with Thomas. Enraged, Edith stabs Lucille with her pen, and then tries to escape. Thomas burns the papers and begs his sister to join him and start a new life. Lucille quickly realizes that Thomas would like Edith to accompany him. In a rage of jealousy, she kills him by stabbing him in the face and then chases Edith. With Thomas ghost, who serves as a distraction, Edith killed Lucille with the help of a shovel. Edith is silently wishing Thomas goodbye before he disappears.
Edith and Alan are saved by the village. Lucille is made the black ghost at Allerdale Hall and can stay in the mansion and play the piano until the end of time. The end credits reveal that Edith wrote Crimson Peak based on her own experiences.