Crimson Peak In Buffalo, New York, 1887, American heiress Edith Cushing is the daughter of a wealthy businessman Carter Cushing. Edith’s ghost is a black and disfigured ghost who was her mother, appears to her at night. She warns her to be careful of Crimson Peak.
Edith, now a budding writer is introduced to Sir Thomas Sharpe in 1901. He is an English baronet as is his sister Lucille. Sharpe is seeking investors to fund his creation, a dig machine which he hopes will bring back the defunct clay mines of his family’s estate. Sharpe’s idea and his inability in raising capital previously make Mr. Cushing unimpressed and he dismisses the idea. Nevertheless, Thomas charms an initially prickly Edith and the two begin to fall in love. Thomas asks Lucille to give him her engagement ring. It’s a family heirloom, which she offers to Thomas with the condition that it will be returned to her. Crimson Peak HD
Cushing isn’t a fan of Sharpes, and employs Mr. Holly as a private investigator. Holly discovers some unsavory information concerning the Sharpes’ family. Mr. Cushing then bribes the couple to quit America immediately. In addition he demands that Thomas “break Edith’s love for her,” leading Thomas to make fun of her by criticizing her novel. Thomas returned Edith’s novel the following day, along with a letter explaining the actions he took. Edith accepts Thomas’s offer and the couple eventually reconcile. On the same day the following day, Mr. Cushing was brutally killed at his club. Edith refuses Dr. Alan McMichael’s plea to investigate the matter further.
Following the funeral Edith marries Thomas and the couple departs to England. They land at Allerdale Hall in Cumberland. The Sharpes mansion, which is crumbling, is sinking slowly into the Red Clay mine it is on top of. The mansion is being degraded every day by the elements. Lucille seems cold towards Edith as Thomas is distant physically and their marriage not consumed. Lucille sips tea made from “firethornberries” in a maniacal way and Thomas convinces Edith to get the first part of her father’s estate so that he can continue to build his miner. As winter draws near, Thomas mentions that the estate was named “Crimson Peak” because of the red warm clay that was able to penetrate the snow. The siblings talk about how their brutal father squandered the wealth of the family, while their mother was harsh and distant.
Edith grows weak and begins to cough up blood. She suffers from frightening nightmares, and she sees horrific, skeletal, and ghosts in red around Allerdale. It tricked her into opening a closet where she found wax Phonograph Cylinders. She chased them down to the cellars, where she found an abandoned trunk that was locked and had “Enola” on it.
Thomas takes Edith on a trip to the local post office, which is where the clerk of the post office writes her an e-mail from Italy addressed to E. Sharpe. Thomas and Edith are snowed in for the night and take the opportunity to finally make their love. Lucille is furious with Edith who isn’t sleeping with Thomas when they come back.
One of the keys Lucille has on her person bears the word “Enola” When Lucille is distracted, Edith steals it. She uses it to unlock the trunk of the cellar. Edith is then able to locate a gramophone that she can utilize to play the wax cylinders in the closet. The letter and her post office show that Thomas had previously been married to three wealthy women, one being Enola Sciotti, an Italian. Edith realizes Lucille is poisoning her , and the siblings are involved in a “marriage and murder” scheme to help themselves and fund Thomas inventing. When Edith is about to confront her sister and husband, she catches them in an incestuous embrace. Lucille is pushed by Edith off a balcony in an attempt to kill her, but she only breaks her leg.
In America, Alan discovers what Mr. Cushing discovered about Sharpes before his death: Thomas’s multiple marriages and Lucille’s admission to a mental hospital. To save Edith the girl, Alan travels to Allerdale Hall during winter. When Alan arrives, he finds Edith injured, but when he wants to take Edith back to her village, Lucille refuses. By now, Thomas has fallen in love with Edith and is suffocated by Lucille, and wants to leave her. Lucille is stabbed by Alan in the underarm and then demands that Thomas complete the task. In a bid to safeguard Edith, Thomas inflicts a non-fatal stab wound on Alan’s stomach. He then hides the victim. Lucille makes Edith sign a transfer deed giving the Sharpes the full title to the estate. Edith also confesses to having killed Thomas and his wives. She also confesses that she had a child with Thomas but that it passed away shortly after the birth. Edith’s father also was murdered by Edith’s mother. Edith’s father was also found having a sexual relationship with Thomas. Edith is furious and attacks Lucille by using her pen, and tries to flee. Thomas burns the transfers and begs his sister to go with him and start with a new beginning. Lucille soon realizes that Thomas would like Edith to go with Thomas. In a jealous rage Lucille kills her by stabbing his face in the process and then chases Edith. With Thomas’ ghost serving as a distraction, Edith murders Lucille with the help of a shovel. Edith silently bids Thomas goodbye before he vanishes.
Edith as well as Alan are rescued by people living nearby, and Lucille becomes the black ghost of Allerdale Hall, remaining in the mansion where she can play her piano for the rest of eternity. The credits at the end indicate that Edith composed Crimson Peak based on her own experiences.