The chapter opens with Dr. Armstrong dreaming that he is in the operating room. As he examines the scalpel, he notes how easy it would be to perform a murder with it. And he knows that he is performing a murder. A handkerchief covers the patient's face, and he longs to know the patient's identity. Suddenly, he understands that the patient is Emily Brent, but as he removes the handkerchief, he sees that the patient is actually Marston. Armstrong is forcibly wakened from his dream by Rogers, who informs the doctor that he can't wake his wife.
Armstrong accompanies Rogers to his wife's bed, and Armstrong quickly confirms that Mrs. Rogers is dead. Rogers informs Armstrong that Mrs. Rogers' health was generally good but that she didn't sleep particularly well. Armstrong confirms that Mrs. Rogers hadn't taken any medication prior to going to sleep.
As the time for breakfast arrives, Macarthur and Wargrave are pacing on the terrace. Claythorne and Lombard have hiked to the summit of the island, where they find Blore, looking toward the mainland. As Lombard looks about, he asserts that a storm is approaching. On the way back to breakfast, Lombard and Blore discuss the likelihood of Marston killing himself.
At breakfast Brent comments that Rogers looks ill. Armstrong states that he has some issues to discuss with the group after they eat. As the men and women eat, they consciously avoid discussing the island. Following breakfast, Armstrong announces that Mrs. Rogers died in her sleep. Wargrave enquires about the cause of death, but Armstrong states that he could not determine it. Brent then suggests that Mrs. Rogers died as a result of her conscience. Blore rebuts her assertion, but Brent remains steadfast in her belief. Blore asks what Mrs. Rogers ate last evening, and Armstrong informs him that Rogers confirmed she had consumed nothing. Blore insinuates that Rogers might be lying, pressing the point that Rogers may have killed her to cover up their involvement in Miss Brady's death. Macarthur argues that a man certainly wouldn't murder his wife; Blore laughs at the comment. When Rogers enters, he apologizes that the food wasn't up to par since the boat from the mainland was late. When Wargrave asks what time the boat usually arrives, the group learns that it is several hours overdue.
Alone on the terrace, Blore and Lombard discuss the late boat. Blore asserts that the boat's late arrival is part of a carefully orchestrated plan. When Lombard asks if Blore believes the boat isn't coming, Macarthur proclaims that the boat isn't coming and that none of them will leave the island. Somehow Macarthur seems comforted by the notion. As Macarthur walks away, Blore accuses him of being daft.
Rogers has a private conversation with Armstrong, in which Rogers asserts that although there were ten Indian figures when the group arrived, a fact which Armstrong confirms, when he was cleaning up last night he noticed that there were only nine figures. Now, there are only eight.
Armstrong's dream reinforces themes of guilt and conscience; Armstrong may be able to hide his secret from others, but he cannot hide it from himself. The dream also brings forth the notion that murder is easy to commit. Brent's comment that Mrs. Rogers died of "conscience" can be seen as reflecting her own guilty conscience.
MacArthur and Wargrave's pacing illustrates a certain level of nervousness is building among the guests.
Lombard's recognition of an approaching storm symbolizes the criminal and psychological storm that will soon overtake the guests.
Blore's declaration that Mr. Rogers may have murdered his wife enhances the theme of mistrust. His assertion that the late boat is part of a carefully orchestrated plan is the first indication of Wargrave's elaborate plot.
The fact that Macarthur is comforted by the boat's failure introduces the notion that a well-kept secret can induce suffering.