I have wanted—let me admit it frankly—to commit a murder myself. . . . I was, or could be, an artist in crime!
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.