This letter was sent to Scotland Yard by the master of the Emma Jane fishing trawler. The writer says that he has been a mass of contradictions since his youth. He has always had a romantic side: the side that is attracted to throwing a bottle in the sea with an important note, which is why he is writing this confession, putting it in a bottle, and throwing it into the sea.
The confession of the murder has been put in a bottle and thrown out to sea. The author, and murderer, starts by explaining his past.
At the same time he has always taken a sadistic delight with seeing or causing death, as well as a strong sense of justice. He hates the idea that an innocent person or creature should suffer – he has always “felt strongly that right should prevail.”
These natural tendencies led him to enter the legal profession. Crime and punishment has always fascinated him and he loves reading detective novels. He also loves to see a criminal in court, and to sentence them to death. He has never sentenced an innocent person, and has always told the jury that there was no case in such situations. He has a reputation as a hanging judge but he says he has only ever drawn the jury's attention to the actual evidence of a case and kept them away from emotional judgments.
These combined obsessions led him to eventually become a judge. This way he could preserve justice, decide between right and wrong, and also sentence people to death. He says that he never tried to get a death sentence when someone was innocent.
For some years he has felt that he wanted to act rather than judge. He wanted to commit a murder himself. He wanted to commit something theatrical and impossible. But he was restrained by the sense that the innocent should not suffer.
Then one day he was talking to a doctor who mentioned how often murders must be committed that the law is unable to touch. The doctor then told the letter writer about the case of Mr. and Mrs. Rogers. The doctor believed that they had withheld medicine from the old woman in their care, but he had no way of proving it. Wargrave then realized that this was his opportunity to commit the perfect murder.
The author of the letter and the murderer, Wargrave, realizes that he could justifiably (to himself) murder people who had committed crimes that were out of the reach of the law. He believes that they deserve death, so he could kill them himself.
He remembered a rhyme from his childhood about ten little soldier boys and began collecting his victims. He heard about Armstrong while at a nursing home. He heard about General Macarthur from a conversation with two old military gossips in his Club. He selected Marston from a large group of people who had committed similar offenses; he heard about Miss Brent while traveling in Majorca. He heard about Blore through his own line of work in the legal system and a man who had returned from the Amazon told him about Lombard.
He slowly and carefully begins looking for people who have committed crimes without being punished.
Finally he ran into a man named Hugo Hamilton while crossing the Atlantic. Hugo was drunk and told him about a woman who took a kid out to sea and let him drown. Hugo knew the moment he looked at her that she had done it. What she didn't realize was that Hugo, whom she had loved, had loved the kid.
This is the story of Vera's Hugo – she killed Cyril, the child, in order to marry Hugo. Yet Hugo, despite loving Vera, also loved Cyril. And the realization of what Vera had done destroyed his love for her and filled him with his own guilt.
Finally he found Morris as the tenth victim. He was a dope peddler who had gotten one of Wargrave's friend's daughters to take drugs. The girl then committed suicide at 21.
Wargrave needed Morris to organize the details, and also chose him because he too was guilty (and therefore, according to Wargrave's moral system, eliminatable).
He did not act on the plan for a long time, but he finally decided to act when he learned from a doctor that he was ill and would die soon. He wanted to die in a blaze of excitement.
Wargrave makes the murders his last act. He knows that he has to go about it when he is going to die soon.
He used Morris to acquire the island and create believable invitations for each of his victims. It worked, and each of the guests arrived on August 8th. To take care of Morris, Wargrave gave him a pill, which he said was for indigestion, and told him to take it last thing at night.
Wargrave has so carefully planned out his mission that it goes exactly as he wants it to from the very beginning.
Wargrave chose the order of his victims very carefully. He believes that there were differing levels of guilt and he wanted the most guilty to suffer the longest. He believed that Marston had no conscience or moral responsibility and that Mrs. Rogers had been influenced by her husband. For Marston he used potassium cyanide which one can easily buy to kill wasps. During his sickness, Wargrave had been prescribed Chloral Hydrate which he kept until he had a lethal amount. He slipped this into Mrs. Rogers' brandy.
Even though everyone was being killed, Wargrave varied the sentences by making some suffer longer. He killed those who held the least responsibility for their murders first. He believes that this plan is the must just. He wanted the most guilty to suffer their guilt the longest.
Macarthur did not hear Wargrave sneak up behind him and his death was quite painless. Wargrave knew that he now needed an ally to complete the rest of his murders. He chose Armstrong because he knew Armstrong was a gullible man. Armstrong suspected Lombard, and Wargrave pretended to agree with him. He said that he had a scheme to make the murderer incriminate himself.
Wargrave needed help in order to finish his plan. He was able to fake his own death with the help of the gullible Armstrong.
On the morning of August 10th Wargrave killed Rogers while he was chopping sticks. While they were looking for Rogers, Wargrave slipped into Lombard's room and stole his revolver. And at breakfast he slipped the last bit of chloral into Miss Brent's coffee. Then when everyone left the room he injected her with cyanide and brought the bumble bee into the room to fit the nursery rhyme.
Wargrave's plan was so tight that no one even knew that he was sneaking around. In spite of his own cold-blooded and insensitive ways, Wargrave has an incredible sense of human psychology and seems to always know what people will do in every situation.
Next he convinced Armstrong that he (Wargrave) needed to be the next victim because this would rattle the murderer, who wouldn't expect it. They used some plaster of red mud on his forehead and Armstrong pronounced him dead after all the fuss with Vera screaming in her room.
This is how Wargrave really got away with the crime. By taking himself out of the picture he made sure that the guests suspected each other so they could not ever truly work together to save themselves.
Armstrong and Wargrave met in the middle of the night and Wargrave led Armstrong far away from the house because he convinced Armstrong that no one should see them. Wargrave then pushed Armstrong over a cliff. Wargrave returned to the house and intentionally made some noise in Armstrong's room to wake the others up. They saw him walk through the door but he looped back into the house and got into bed because he knew that they would search the house again but not look too carefully at any of the corpses.
Wargrave has great control over his body even though he is a dying old man. The fact that everyone was locked in their rooms, as he knew they would be, helped.
Wargrave then writes that he forgot to mention that he returned the revolver to Lombard's room. He had hidden it in a food tin at the bottom of the pantry. He had hidden the red curtain under one of the drawing room chairs.
Although this seems unnecessary at first, placing the revolver back in Lombard's room ensured that Vera could kill Lombard.
He knew that the three people would now be terrified of each other and one of them would have a revolver. When Blore came up to the house, Wargrave pushed the marble clock onto him. From the window he watched Vera shoot Lombard and then wondered excitedly whether she would play into the stage he set for her in her bedroom.
Wargrave seems to be almost omniscient. He knew, based on their characters, that Blore would separate himself from the group and that Vera was actually braver and more ruthless than Lombard.
Wargrave writes that he thinks this is an interesting psychological experiment: would she cave to her own guilt? He thought she would and he was right. Vera hanged herself in front of Wargrave's eyes as he hid behind the wardrobe. He then returned the chair to its place against the wall and finds the revolver.
At this point Wargrave wanted Vera to hang herself, and thought she would, but he also could have killed her himself if she didn't. But her guilt overtook her in the end. He moved the chair back to confuse everyone.
At this point he writes that he will now finish this letter and put it in a bottle. He wanted to invent a murder that no one could solve but he knows he will not be satisfied unless there is the possibility that someone will find out about his brilliance.
His pride in his own careful task and sense of extreme justice means he hopes someone will figure out the murder eventually. It is important t him to be seen as a man who committed the “perfect” crime.
He believes that the mystery will remain unsolved but there are three clues. 1. The police know that Edward Seton was guilty and that therefore out of the ten people only one is innocent. 2. From the rhyme they know that Armstrong's death was a “red herring” so at this moment there must have been something strange going on. 3. A symbolic reason: the mark of Cain on Wargrave's head.
The mark of Cain on Wargrave's head (the wound on him) shows that he is the secret murderer, just as Cain was a murderer in the Bible. This allusion also implies that Wargrave know that although he was doing this out of a sense of justice, he is also evil himself.
After throwing the letter into sea, Wargrave writes that he will go up to his room and attach an elastic cord to his glasses, he will lay on his glasses and will loop the cord around the door handle and attach it to the revolver. His hand, protected by a handkerchief, will press the trigger and the revolver will recoil to the door having been pulled by the elastic cord. The elastic will just hang down from the glasses and the handkerchief will rest on the ground. It will look as if he were shot through the head as the accounts claim.
Wargrave very carefully kills himself at the end to make it appear as if he were murdered. He knows that he is already sick and he has committed his last great act of his life so he feels no fear or worry about dying.