Pennington is shocked that his revolver was used to commit murder and maintains that he was quietly writing letters the whole time, though he can’t produce a witness. Pennington tries to explain how someone would know about his revolver and says he mentioned it in the saloon one evening when most of the other passengers were around to hear. Poirot invites Pennington to his cabin in half an hour to discuss the case in more detail.
Pennington has some fairly crucial evidence against him and no one to confirm his alibi when Mrs. Otterbourne was shot. Poirot knows all this and hopes to get some good information out of him.
Race and Poirot leave Pennington, agreeing that he seems afraid. As they reach the promenade deck, Mrs. Allerton comes up to them and offers to share a double cabin with Rosalie, so she doesn’t have to go back to the one she used to keep with her mother. Poirot agrees that this is a good idea.
Mixed in with the mystery are little moments of character development, such as this one which suggests that Mrs. Allerton is becoming closer to Rosalie. Little moments of kindness like this make the overall tone of the novel less cynical, as it suggests that it’s possible for people from different backgrounds can come together rather than clash with one another.
Cornelia comes onto the deck. She asks Poirot how the culprit could’ve possibly gotten away. Poirot mentions three distinct escape routes, and Jacqueline notes that the murderer could have swung over the railing onto the deck below. Tim notes that this would be possible since there’s a brief period of shock after a gun goes off. Race asks everyone to clear the area so that they can bring out the dead body.
As always, the characters lay out different possibilities to establish what’s plausible and what isn’t. If the shooter really did swing over the deck (it seems possible, in theory, anyway), then it would limit the shooter to characters in good physical shape.
As he leaves the area, Poirot overhears Ferguson and Cornelia arguing about Western and Eastern attitudes toward death. Ferguson calls Linnet, Louise, and Mrs. Otterbourne all parasites, but Cornelia defends them. As Poirot passes, Ferguson angrily tells him that Cornelia’s father was financially ruined by Linnet’s and died in poverty, and yet still Cornelia defends Linnet. Cornelia says of course she felt bad for her father, but that she prefers to focus on the future. Ferguson agrees and quite suddenly proposes to marry her. She takes it as a joke, but he insists he’s serious. Ultimately, she says Ferguson just wouldn’t be reliable, and she leaves in a hurry for her cabin.
Ferguson continues his efforts to be noticed by once again commenting approvingly on the murders. His attempt to impress Cornelia clearly isn’t working. His lack of seriousness is further emphasized when he proposes to Cornelia—it’s not a joke, but it is a sign that Ferguson isn’t a particularly practical character, given that he's willing to propose to someone he just met who doesn’t even like him.
Ferguson asks Poirot what he thinks of Cornelia. Poirot responds that “she has a great deal of character,” which Ferguson agrees with. He goes over to Miss Van Schuyler and asks permission to marry Cornelia. He admits that Cornelia refused him but insists that he’ll keep trying until she says yes. Miss Van Schuyler is not pleased. When he asks what Miss Van Schuyler has against him, she says it should be obvious: social position. Cornelia comes back and confirms that she definitely hasn’t encouraged Ferguson in any way. She says she finds him outrageous. Leaving Miss Van Schuyler furious, Ferguson at last goes on his way.
The book leaves aside the central mystery for a moment to look at class expectations and romance. Miss Van Schuyler disapproves of Ferguson simply because of his lower class status, suggesting that she sees marriage as a strategic move rather than an expression of genuine love. Like Linnet, Ferguson seems to be someone who isn’t used to hearing the word no, and his pursuit of Cornelia is centered on what he wants rather than what she wants.
Miss Van Schuyler asks Poirot to send her Miss Bowers, because Ferguson has so upset her. Poirot notes that Ferguson is “rather eccentric” and “spoilt.” He asks if Miss Van Schuyler recognizes him, then reveals that Ferguson is actually Lord Dawlish, who’s incredibly wealthy but who became a communist at Oxford. Miss Van Schuyler is shocked but thanks Poirot for the information. Poirot smiles as he watches Miss Van Schuyler leave the saloon, but then he has a thought that makes him become more serious and nod his head.
Poirot finally reveals that he knew all along why Ferguson was acting so strange: he is in fact a member of the aristocracy who is slumming it under a fake name because he recently discovered communism. The humor in this scene comes from the fact that if Miss Van Schuyler had known his identity earlier, she likely would’ve begged Cornelia to marry Ferguson (a.k.a. Lord Dawlish) rather than shooing him away.