Although he was married to an Egyptian woman, Fleetwood attempted to romance Marie, a former chambermaid of Linnet Doyle. When Linnet discovered that he was already married and had three children, she warned Marie and caused them to break up. This led Fleetwood to bear a grudge against Linnet and made him a plausible suspect in her murder.
Louise Bourget tells Poirot and Colonel Race that Fleetwood had found out that the Linnet Doyle who was on the boat had formerly been Linnet Ridgeway. According to Louise, he had said that he would like to kill Linnet, and that her interference had ruined his life.
When interviewed by Poirot and Colonel Race, Fleetwood says that the woman he married had gone back to her people, and he had not seen her for "a half a dozen years". He says that he would have treated Marie right, and she would never have found out about the other woman if it had not been for "that meddlesome young lady of hers".
Fleetwood admits that he did have a grudge against Linnet, and that he felt bitter about it when he saw her on the boat "all dressed up in pearls and diamonds and lording it all over the place", unaware that she had "broken up a man's life for him".
Fleetwood does not appear in the 1978 Ustinov film adaptation. However the plotline of one of Linnet's maids wanting to marry an already married man is used, although not with Marie but with Louise Bourget. She wants to resign to marry the man but Linnet refuses to allow it. The man in question is not, however, named, and is not likely to be a member of the Karnak crew.