While on holiday in Cairo to board the steamer Karnak, set to tour along the Nile from Shellal to Wadi Halfa, Hercule Poirot is approached by successful socialite Linnet Doyle. She wants to commission him to deter her former friend Jacqueline de Bellefort from hounding and stalking her: Linnet had recently married Jacqueline's fiancé, Simon Doyle, which has made Jacqueline bitterly resentful. Poirot refuses the commission, but attempts unsuccessfully to dissuade Jacqueline from pursuing her plans further. Simon and Linnet secretly follow Poirot to escape Jacqueline, but find she had learned of their plans and boarded ahead of them. The other Karnak passengers include Linnet's maid (Louise Bourget) and trustee (Andrew Pennington), romance novelist Salome Otterbourne (a thinly-disguised portrayal of Elinor Glyn) and her daughter Rosalie, Tim Allerton and his mother, American socialite Marie Van Schuyler, her cousin Cornelia Robson and her nurse Miss Bowers, outspoken communist Mr. Ferguson, Italian archaeologist Guido Richetti, solicitor Jim Fanthorp, and Austrian physician Dr. Bessner.
