Hosted by the renowned opera singer Rowena Drake (Kelly Reilly) at her rumored-to-be-haunted palazzo, the séance attended by Poirot aims to contact Rowena’s deceased daughter, Alicia, under mysterious circumstances. Famed medium Joyce Reynolds (Michelle Yeoh) conducts the ceremony, with Ariadne seeking inspiration for her writing. Skeptic Poirot agrees to expose Reynolds as a fraud but is thrown into a complex whodunit when Reynolds is fatally impaled. Amidst stormy chaos, Poirot locks everyone inside, including Ariadne, Rowena, Alicia’s estranged former fiancé Maxime, housekeeper Olga, Drake family doctor Leslie Ferrier, Dr. Ferrier’s son Leopold, assistants Desdemona and Nicholas, and Poirot’s bodyguard. After attempts on Poirot’s life, ghostly sightings, and Dr. Ferrier’s death, Poirot unravels the truth. Ariadne orchestrated the case to challenge Poirot, and Rowena, having poisoned her daughter Alicia to keep her close, emerges as the killer. The plot involves blackmail, staged murders, and Rowena framing Poirot, revealing a web of deceit. As Rowena attempts to flee, Poirot chases her to Alicia’s bedroom, where she falls from the balcony as a ghostly apparition of Alicia appears, leaving the reality of the ghost ambiguous.