Wargrave closes by describing the mechanism by which he will pull the trigger of the revolver from a distance and have the revolver flung away by an elastic band, thereby shooting himself so that he falls back on his bed as though laid there by the others. He concludes that men from the mainland “will find ten dead bodies and an unsolved problem on Indian Island.”
The traditional detective story ends with a scene in which the sleuth, having carefully considered all the evidence, gathers the characters together and explains everything that has happened, concluding by unmasking the killer. Something similar takes place in the epilogue to And Then There Were None, although the police detectives are utterly baffled by what has transpired, and it is left to another character to explain things and untangle the mystery. Here, this other character is Wargrave, the murderer. Instead of being investigated and solved by a master detective, the ten murders in this novel can be solved only by the man who has committed them.
The unorthodox structure of this plot begins to make sense when we consider the themes that Christie has been exploring: specifically the effects of conscience and the administration of justice. These are classic detective-fiction themes, but Christie gives them a different spin by making her murder victims guilty of other murders unpunishable by any legal means. One can argue that the killings on Indian Island are not crimes at all but rather acts of ultimate justice. Wargrave is not killing for personal gain; rather, he is simply doing with his own hands what he did through the agency of law while he was still a judge. Seen in this light, Christie’s decision to have him play the detective role and explain the mystery to the reader makes a certain kind of sense. In a traditional mystery story, the detective is the agent of justice, stepping in when a crime has been committed and assuring that the murderer is duly punished. In this story, Wargrave is doing exactly that, albeit by stepping outside the bounds of the law and becoming a killer himself.
Of course, there are objections to seeing Wargrave’s actions as just. For example, one might point out that not all the crimes that he punishes are really deliberate and premeditated murders. However much we may despise Emily Brent, for instance, she did not actually kill her servant; Emily merely fired her, and the servant committed suicide. Similarly, however appalling a human specimen Tony Marston may be, his running over of two children was accidental. The same lack of malice characterizes Dr. Armstrong, who did not intend to kill the woman who died on his operating table. Armstrong and Marston’s actions may have been heinous, but one could argue that they don’t deserve to die. Christie goes out of her way to make us sympathize with Wargrave’s victims, despicable though their actions may have been.
Wargrave himself, meanwhile, is a markedly unsympathetic character. He presents himself as an agent of justice, but he admits to experiencing a perverse pleasure in the taking of life, beginning with the “various garden pests” that he killed as a boy and continuing through his human victims. He is just but not at all merciful, and he kills with enthusiastic cruelty. He is also grandiosely arrogant; his conception of himself as an “artist” reduces his victims from human beings to mere means toward his selfish ends. Indeed, he writes his confession only because he cannot bear the idea that his perfect crime will go unappreciated.
At its conclusion, Christie’s novel both does and does not reassert moral order. Wargrave’s actions do not go unpunished; he shares the same fate as the people he has murdered. He has become a murderer himself, and so, under his own code of justice, he cannot be allowed to live. In this regard, Christie returns to the neat moral symmetry of the classic detective story: the guilty receive what they deserve, and no one gets away with murder. At the same time, however, Wargrave would have died of a terminal illness in any case, and by killing himself he merely asserts authority over death. He arranges his death in a way that thrills him, and dies a happy man and a proud artist. Christie allows us to feel the satisfaction of finally understanding the mystery, but she does not allow us the satisfaction of seeing the murderer sniveling, angrily led away in handcuffs, or humiliated in front of the world. Wargrave never loses his control or his murderous sense of justice.