Agatha Christie’s detective novel featuring Hercule Poirot is set primarily in Egypt on a boat going down the Nile. Several murders are committed and Poirot, the well-known Belgian detective, is called upon to solve them. The novel begins in England, however, with an apparent love triangle between two young women who are old friends and a young man who is engaged to one of them. Jacqueline de Bellefort, who is engaged to Simon Doyle, goes to visit Linnet Ridgeway to ask her to give Simon a job. Linnet has just inherited a lot of money, Jackie has very little, and Simon has none. Linnet agrees after her friend persuades her of his many virtues. However, Simon soon breaks off his engagement to Jackie and instead marries Linnet. This turn of events sets in motion the rest of the plot. Once they get on the boat in Egypt, the first murder victim is Linnet, who is shot in the head. Of course Simon is the prime suspect.
Sadly, Jackie had followed them on their romantic Nile cruise, which Linnet thought was creepy. Therefore, Jackie is also a viable suspect. In a secondary plot, it is revealed that Linnet’s valuable pearls were stolen from her room. Poirot must determine if the two acts are related. Because of her easy access, Linnet’s maid Louise Bourget could have the pearls, and all the other passengers initially seem to have equally good motives and opportunities. Soon Louise is also murdered, and Jackie accidentally shoots Simon in the leg.
The atmosphere on board is decidedly tense, but Tim Allerton develops a romantic interest in Rosalie Otterbourne. Her mother, a novelist, approaches Poirot about putting him in a novel. She has figured out the murderer’s identity, but she becomes the next murder victim. With the help of his friend Colonel Race, Poirot figures out that and the pearls were stolen by a wealthy American Marie Van Schuyler, who is a kleptomaniac. Following a clue provided by red nail polish, Poirot realizes Simon was not injured; Jackie and Simon had been scheming to defraud Linnet. As the boat prepares to dock, Jackie (who had a second pistol) kills first herself and then Simon so that they will not be prosecuted.