Two policeman, Sir Thomas Legge and Inspector Maine, discuss the perplexing Indian Island case. They have reconstructed much of what happened on Indian Island from diaries kept by various guests. It is clear to them that the murderer was not Blore, Lombard, or Vera. When they arrived, the police found the chair Vera kicked away to hang herself mysteriously set upright against the wall. We learn that Isaac Morris, who hired Lombard and Blore and bought the island in the name of U. N. Owen, died of an apparent sleeping-pill overdose the night the guests arrived on the island. The police suspect that Morris was murdered. The police know that the people of Sticklehaven were instructed to ignore any distress signals from the island; they were told that everything taking place on the island was part of a game being played by the wealthy owners of the island and their guests.

The rest of the epilogue takes the form of a manuscript in a bottle, found by a fisherman and given to the police. It is written by Judge Wargrave, who writes that the manuscript offers the solution to an unsolved crime. He says he was a sadistic child with both a lust for killing and a strong sense of justice. Reading mysteries always satisfied him. He went into law, an appropriate career for him because it allowed him to indulge his zeal for death within the confines of the law. Watching guilty persons squirm become a new pleasure for him. After many years as a judge, he developed the desire to play executioner. He wanted to kill in an extraordinary, theatrical way, while adhering to his own sense of justice. One day, a doctor mentioned to Wargrave the number of murders that must go unpunished, citing a recently deceased woman he felt sure was killed by the married couple who worked as her servants. Because the couple withheld a needed drug in order to kill her, the murder could never be proven. This story inspired Wargrave to plan multiple murders of people who had killed but could not be prosecuted under the law. He thought of the “Ten Little Indian” rhyme that he loved as a child for its series of inevitable deaths.

Wargrave took his time gathering a list of victims, bringing up the topic of unpunished murders in casual conversations and hoping someone would mention a case of which they knew. Wargrave learned he was terminally ill and decided to kill himself after doing away with his victims. Wargrave’s tenth victim, we learn, was Isaac Morris, who acted as his agent in making the arrangements for Indian Island, and who had been responsible for selling drugs to a young acquaintance of Wargrave, who subsequently killed herself. Before leaving for Indian Island, Wargrave gave Morris poison, which he claimed was a cure for Morris’s indigestion.

Wargrave killed Marston and Mrs. Rogers first, he writes, because they bore the least responsibility for their crimes—Marston because he was born without a sense of moral responsibility, and Mrs. Rogers because she was under the sway of her husband when they murdered their elderly employer. Next he killed General Macarthur, sneaking up on him near the ocean. Wargrave goes on to describe how he tricked Armstrong into becoming his ally: Armstrong, he notes, “was a gullible sort of man . . . it was inconceivable to him that a man of my standing should actually be a murderer.” He notes that he killed Mr. Rogers while the butler was out chopping sticks. At breakfast, he poisoned Emily Brent. Later, Armstrong agreed to help Wargrave fake his death, and pretended to examine the body of the judge and find a gunhot wound on his forehead. Wargrave arranged to sneak out and meet the Armstrong by the shore that evening. There, he pushed Armstrong over a cliff into the ocean.

After Armstrong’s death, Wargrave returned to his room and played dead. Killing Blore was easy, since the ex-policeman foolishly came up to the house alone, and Wargrave then watched with satisfaction as Vera disposed of Lombard. Wargrave writes that he would have killed Vera himself, but he wanted to make her death fit the rhyme, so he set up her room in a suggestive way, with a noose hanging down and the smell of the sea wafting in, letting Vera’s own guilt drive her to suicide.

Wargrave says he wrote the manuscript because he takes an artist’s pleasure in his own work and wants recognition. He wonders if the police will pick up on three clues: first, that Wargrave was the odd man out—he was not really guilty of a murder, as the rest were, since in condemning Edward Seton to death he condemned a guilty man. Second, the line about the “red herring” points to the fact that Armstrong was somehow tricked into his death. Third, Wargrave’s death by a bullet through the forehead will leave a red mark like the brand of Cain, the first murderer in the biblical book of Genesis.

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.