Claythorne and Lombard are stunned. In a heated exchange of words, it seems that they now suspect each other of being the murderer. Claythorne suggests that they retrieve Armstrong's body and place it with the others in the house. Lombard rejects the idea, but consents to dragging the body out of the surf. As they struggle to move Armstrong's body, Claythorne bumps against Lombard. Lombard asks if she is satisfied, and she replies "quite", in a tone that lets Lombard know he has been had: Claythorne has taken his revolver. Lombard demands that she return the gun, but Claythorne only laughs. Lombard attempts to rush her, but she fatally shoots him.
Claythorne experiences a deep sense of release and relief that her struggle has ended.
As the sun sets, a mentally shaken Claythorne returns to the house. During her walk she considers that the entire series of events might be a mere dream. She becomes extremely tired and wishes for nothing but sleep. Feeling strangely peaceful, Claythorne enters the house through the front door. As she passes the dining room, she sees the three remaining Indian figurines. She tosses two of them out of the window and keeps the third, telling the figurine that it can come with her because they have "won". As she heads upstairs to her room, she contemplates the final lines of the nursery rhyme. But she misremembers the final line as "One little Indian boy left all alone. He got married and then there were none". The word "marriage" turns her thoughts to Hugo, whom she believes is now waiting for her in her room. At the top of the stairs she unconsciously drops the revolver. As she enters her room, she is surprised to see a rope and noose hanging from the black hook in the ceiling and a chair below the noose. She senses that committing suicide is what Hugo wants her to do, and she then correctly remembers the final line of the rhyme: "He went and hanged himself and then there were none. . . ." The figurine drops from Claythorne's hands as she steps upon the chair and hangs herself.
Claythorne's confiscation of Lombard's revolver and murder of him illustrates how deeply her sense of self-preservation has become. Claythorne's comment to the figurine that they have "won" reflects the fact that the entire experience has been a game for the murderer; the statement is ironic in that even though, aside from the murderer, she is the last living guest, her reward for winning the game is complete isolation, as well as her own death. Her feeling that the entire experience may be a dream and her belief that Hugo has placed the noose and chair for her is further evidence of her break from reality. Of course, Claythorne's willingness to take her own life is the clearest evidence of how deeply she has been shattered by the experience.