Hercule Poirot is enjoying a vacation in Egypt when he encounters a wealthy and beautiful heiress, Linnet Ridgeway Doyle, who is on her honeymoon with her new husband, Simon Doyle. However, their trip is overshadowed by Jacqueline de Bellefort, Simon’s ex-fiancée, who is bitter over Linnet stealing him away. Jacqueline follows them everywhere, making threats and causing unease among the passengers.

During the cruise down the Nile, Linnet is found shot dead in her cabin, with a bullet wound to the head. Her priceless pearls are also missing. Suspicion initially falls on Jacqueline, but she has a seemingly perfect alibi—she was heavily sedated after a dramatic confrontation the previous night. Poirot realizes that nearly everyone on board had a motive, as Linnet had wronged many people in her life.