The Murder of Mrs. Otterbourne is the killing of Salome Otterbourne by Jacqueline de Bellefort, carried out when Salome’s observation threatened to expose Jacqueline’s role in Louise Bourget’s murder. In Hercule Poirot’s reconstruction, it was a rapid response to a danger Simon Doyle recognized and communicated, and it became a second murder committed to protect the conspiracy against Linnet Doyle.

The danger created by Louise Bourget’s death

Louise Bourget had discovered evidence implicating Simon Doyle and Jacqueline de Bellefort in Linnet Doyle’s murder. Jacqueline went to Louise’s cabin, where she killed her; Salome Otterbourne then saw Jacqueline entering the cabin. Salome’s knowledge threatened to connect Jacqueline to Louise’s death, just as Louise’s own knowledge had made her a danger to the conspirators.

Simon Doyle learned that Salome had seen Jacqueline. He asked to see Jacqueline and had Hercule Poirot leave them alone together. Poirot later interpreted Simon’s urgent request and his reaction when Salome approached as a warning to his accomplice: the apparent agitation was not merely nerves, but a signal that Jacqueline had been seen.

The shooting

Jacqueline acted immediately. Remembering that Andrew Pennington had spoken of a revolver, she obtained Andrew Pennington’s Colt Revolver, crept outside the door, listened, and fired when the moment came. Her earlier claim that she was a good shot proved relevant to the success of the attack. Salome was killed before she could disclose what she had witnessed.

Jacqueline’s escape depended on speed and proximity. Poirot reasoned that, after firing, she could discard the revolver, hurry into her cabin, disturb her hair, and lie down on the bunk. Her cabin was two cabins away from Dr. Bessner’s. The maneuver was risky, but, in Poirot’s reconstruction, it gave her a chance to appear to have been elsewhere when the shooting occurred.

Exposure and significance

The attack was not an isolated crime: it followed the carefully timed plan against Linnet Doyle and the killing of Louise Bourget. In recounting the event, Jacqueline acknowledged that she had acted without pausing to think, afraid that Salome would reveal what she had seen. Her admission confirms that the second killing arose from the danger posed by a witness, rather than from a separate dispute with Salome.

The episode also shows why the investigation had to be reconsidered rather than forced into its first theory. Poirot and Colonel Race initially approached Linnet’s murder as a spontaneous act by someone who had overheard Jacqueline and Simon. Poirot later recognized that the murder had been planned, including the drugging of his wine, and that the removal of Jacqueline’s pistol was a fact his earlier explanation could not account for. Salome’s killing belongs to the same chain of concealment: when an unforeseen witness threatened the plan, Jacqueline acted to prevent the truth from emerging.