World-renowned detective Hercule Poirot is on vacation in Egypt, looking to escape his career of crime-solving and tragic personal events. His vacation takes a turn when he encounters the wealthy and beautiful Linnet Doyle, nee Ridgeway, and her new husband, Simon Doyle, during their honeymoon. Accompanying the Doyles is an assembly of friends and acquaintances with various ties to the couple, each with their own secrets and motives. The serene backdrop of the Egyptian pyramids and the Nile's seductive beauty quickly become overshadowed by the undercurrents of jealousy and malice among the group.

Tensions rise when Linnet's former friend, Jacqueline de Bellefort, who was once romantically involved with Simon, follows the couple on their honeymoon cruise in a display of heartbreak and vengeance, making the other guests uncomfortable. Poirot observes these interactions with keen interest but is thrust back into his role as a detective sooner than expected. When a shocking murder occurs aboard the luxurious river steamer, the vacation turns into a complex investigation. With a ship full of potential suspects, each with a plausible motive, Poirot must unravel the tangled web of lies and deceit to uncover the truth behind the murder, before the killer can strike again.