Most murder mysteries examine justice—its violation, through the act of murder, and its restoration, through the work of a detective who solves the crime and ensures that the murderer pays for his or her deed. And Then There Were None examines justice, but it bends the formula by making the victims of murder people who committed murder themselves. Thus, the killings on Indian Island are arguably acts of justice. Judge Wargrave does the work of detective and murderer by picking out those who are guilty and punishing them.

Whether we accept the justice of the events on Indian Island depends on both whether we accept Wargrave’s belief that all the murder victims deserve their deaths and whether we accept that Wargrave has the moral authority to pronounce and carry out the sentences. At least some of the murders are unjust if we do not consider all of Wargrave’s victims murderers. Emily Brent, for example, did not actually kill her servant, Beatrice Taylor. Thus, one could argue that she deserves a lesser punishment for her sin.

Christie explores the line that divides those who act unjustly from those who seek to restore justice. She suggests that unjust behavior does not necessarily make someone bad and enforcing justice does not necessarily make someone good . Wargrave’s victims, although they have violated the rules of moral behavior in the past, are, for the most part, far more likable and decent human beings than Wargrave. Although Wargrave serves justice in a technical sense, he is a cruel and unsympathetic man, and likely insane.

By creating a story in which every character has committed a crime, Christie explores different human responses to the burden of a guilty conscience. Beginning with the first moments after the recorded voice reveals the guests’ crimes, each character takes a different approach to dealing with his or her guilt.

The characters who publicly and self-righteously deny their crimes are tormented by guilt in private. General Macarthur, for instance, brusquely dismisses the claim that he killed his wife’s lover. By the following day, however, guilt so overwhelms him that he resignedly waits to die. Dr. Armstrong is equally dismissive of the charges against him, but he soon starts dreaming about the woman who died on his operating table.

On the other hand, the people who own up to their crimes are less likely to feel pangs of guilt. Lombard willingly admits to leaving tribesmen to die in the African bush, insisting that he did it to save his own life and would willingly do it again. Tony Marston readily owns up to running down the two children, and he displays no sense of having done anything wrong. Neither of the two men gives a moment’s private thought to his crime.

While the ones who do not own up to their crimes feel the guiltiest, no such correlation exists between levels of guilt and likelihood of survival. Conscience has no bearing on who lives the longest, as is illustrated by the contrast between the last two characters left alive, Lombard and Vera. Lombard feels no guilt, and the air of doom that enshrouds the island doesn’t affect him. Vera, on the other hand, is so guilt-ridden that she ends her life by succumbing to the seemingly inevitable conclusion of the “Ten Little Indians” poem and the aura of almost supernatural vengeance that pervades the novel.

And Then There Were None takes place in 1930s Britain, a society stratified into strict social classes. These distinctions play a subtle but important role in the novel. As the situation on the island becomes more and more desperate, social hierarchies continue to dictate behavior, and their persistence ultimately makes it harder for some characters to survive. Rogers continues to perform his butler’s duties even after it becomes clear that a murderer is on the loose, and even after the murderer has killed his wife. Because it is expected of a man of his social class, Rogers washes up after people, remains downstairs to clean up after the others have gone to bed, and rises early in the morning to chop firewood. The separation from the group that his work necessitates makes it easy for the murderer to kill him. Additionally, the class-bound mentality of Dr. Armstrong proves disastrous for himself and others, as he refuses to believe that a respectable professional man like Wargrave could be the killer.

The “Ten Little Indians” rhyme guides the progression of the novel. The singsong, childish verses tell the story of the deaths of ten Indian boys and end with the line that gives the novel its title: “and then there were none.” A framed copy of the rhyme hangs in every bedroom, and ten small Indian figures sit on the dining-room table. The murders are carried out to match, as closely as possible, the lines in the poem, and after each murder, one of the figures vanishes from the dining room. The overall effect is one of almost supernatural inevitability; eventually, all the characters realize that the next murder will match the next verse, yet they are unable to escape their fates. The poem affects Vera Claythorne more powerfully than it affects anyone else. She becomes obsessed with it, and when she eventually kills herself she is operating under the suggestive power of the poem’s final verse.

Dreams and hallucinations recur throughout the novel, usually as a reflection of various characters’ guilty consciences. Dr. Armstrong has a dream in which he operates on a person whose face is first Emily Brent’s and then Tony Marston’s. This dream likely grows out of Armstrong’s memories of accidentally killing a woman on the operating table. Emily Brent seems to go into a trance while writing in her diary; she wakes from it to find the words “The murderer’s name is Beatrice Taylor” scrawled across the page. Beatrice Taylor is the name of Emily Brent’s former maid, who got pregnant and killed herself after Emily Brent fired her. Brent’s unconscious scrawl demonstrates, if not her guilty conscience, at least her preoccupation with the death of her servant. Vera Claythorne often feels that Hugo Hamilton—her former lover, for whose sake she let a little boy drown—watches her, and whenever she smells the sea, she remembers the day the boy died, as if hallucinating.

For most of the novel, a fierce storm cuts the island off from the outside world. This storm works as a plot device, for it both prevents anyone from escaping the island and allows the murderer free rein. At the same time, the violence of the weather symbolizes the violent acts taking place on Indian Island. The storm first breaks when the men carry the corpse of General Macarthur into the dining room, symbolizing the guests’ dawning realization that a murderer is loose on the island.

When Wargrave fakes his own death and then kills himself at the end of the novel, he leaves a red gunshot wound on his forehead—first a fake wound, then a real wound. This wound, as he points out in his confession, mirrors the brand that God placed upon the forehead of Cain, the first murderer in the Bible. It symbolizes Wargrave’s self-admitted links to Cain: both are evil men and murderers.

When the characters arrive on the island, they are treated to an excellent dinner. Soon, however, they are reduced to eating cold tongue meat out of cans. At the end of the novel, both Lombard and Vera refuse to eat at all, since eating would require returning to the house and risking death. The shift from a fancy dinner to canned meat to no food at all symbolizes the larger pattern of events on the island, as the trappings of civilization gradually fall away and the characters are reduced to mere self-preservation.