In the eerie, post-war opulence of a Venetian palazzo, retired detective Hercule Poirot, played by Kenneth Branagh, seeks a quiet life away from the horrors he has witnessed. His self-imposed exile is shattered when a friend, the celebrated mystery novelist Ariadne Oliver portrayed by Tina Fey, lures him to a séance on All Hallows’ Eve. The gathering, hosted by the grieving opera singer Rowena Drake (Kelly Reilly), aims to contact her tragically deceased daughter, but instead summons a palpable and terrifying dread. When a shocking death occurs within the palazzo’s waterlogged, decaying walls, Poirot is forced to confront not only a cunning murderer among the guests—including a skeptical doctor (Jamie Dornan), a secretive housekeeper (Camille Cottin), and a mysterious medium (Michelle Yeoh)—but also the unnerving possibility that supernatural forces are at play. Blending the intricate puzzles of a classic whodunit with genuine moments of gothic horror, this atmospheric thriller traps Poirot in a labyrinth of secrets, where every echo in the shadowy hall could be a clue or a ghost, and trusting his legendary logic becomes a battle against his own rising fear.