In this gothic horror adaptation of Agatha Christie's novel Hallowe'en Party, the retired Hercule Poirot is drawn back into an investigation after a guest is murdered during a séance. Set in a decaying Venetian palazzo on a stormy All Hallows' Eve in 1947, the legendary detective finds his rational mind challenged by supernatural occurrences while he works to uncover a human killer. Trapped with a cast of suspicious characters, Poirot is thrust into a chilling world of shadows, secrets, and ghosts as he attempts to solve the case.