Agatha Christie examines the psychology of the island’s guests, as each deteriorates under the pressure of guilt and grave danger. At first, the guests hide their guilt not only from others but also from themselves. This is possible because their crimes are perceived as accidental and unintentional; a number are also passive-aggressive. Vera Claythorne, General MacArthur, Mr. Blore, Emily Brent, Mr. and Mrs. Rogers, and Philip Lombard all deny any active agency in the deaths they are said to have caused. Instead, each could be said to have betrayed a trust by failing to act. For instance, Vera failed to stop the boy she looked after from swimming too far from shore; Mr. and Mrs. Rogers withheld needed medication; Emily Brent failed to demonstrate compassion for her maidservant; Mr. Blore and General Macarthur hid their crime under the rubric of duty.

While these characters maintain a show of innocence, however, their guilt emerges less consciously, through dreams or memories that undermine their self-assurance and certainty. Thoughts of their victims trouble a number of the guests. Emily feels haunted by the spirit of her servant; for Vera, the smell of the sea seems to summon the spirit of the drowned boy. These episodes point to the way in which guilt, even if denied by the rational faculties, can make its presence felt in other ways. Vera is tormented by her unbidden fantasies and memories to such an extent that she is no longer in her right mind by novel’s end. She readily cooperates with the suggestion of the nursery rhyme, hanging herself on the noose the judge has provided.

Related to the psychology of the guilty is the theme of exposure. The isolated island mansion is modern, flooded with light, indicating a venue in which all will be revealed. Each guest exposes a side far from rational and decent. Bestial metaphors suggest that, under duress, each has reverted to a primitive law of the jungle, participating in a war of all against all. This disturbing Darwinist vision is first articulated by Philip Lombard as a justification for his crime, but as the characters are reduced to their instincts for self-preservation, the originally paradisaical island becomes a hellish jungle.

The law of the jungle does momentarily reward the intellectually and physically agile Vera, who murders Lombard with his own gun. The hardened mercenary Lombard, whose conviction of racial superiority had justified his abandonment of native Africans, also believed that he was superior to any woman, at first dismissing the idea of female mastermind behind the murders. Lombard lives to see Vera outsmart him, but Vera’s humanity, not her Darwinian survival instinct, prevails—she has utterly disintegrated psychologically under the pressure of her nerve-racking situation and the promptings of her own guilty conscience. Far from triumphant, she becomes the final victim of Justice Wargrave.

A brilliant psychologist himself, the judge in the end discloses his own character and motive. The artfully composed letters and the mysterious recorded voice of Mr. “Unknown” are two early indications that the mansion’s visitors are being subjected to the manipulations of a “mastermind.” As an experienced judge, Wargrave is able to turn all the guests against one another and to enlist the most useful of them as an ally.

In his manuscript, Wargrave admits that he became a judge because sentencing criminals to death allowed him to exercise his sadistic impulses free of the qualms of conscience. Wargrave does not simply execute his guests, however. Each victim plays a part in the judge’s ruthless theatrical reinvention of the punitive nursery rhyme. He characterizes himself as a creative genius, seeing his success at controlling the fates of his guests as an artistic achievement. The nursery rhyme allows the judge to become a playwright and stage manager, with each guest assigned a role. The rhyme further produces an uncanny inevitability; the executions are carried out as if they were the product of an inexorable godlike mechanism.

The judge confesses that he sees himself as an avenging deity, replacing both human and divine justice in favor of his own. He acknowledges this through the symbolism of his bullet wound, which, he explains, is the “mark of Cain,” misreferencing the biblical story in which God set a mark of protection upon the unscrupulous Cain when he took the law into his own hands, murdering his brother, Abel. This reference may recall Emily Brent’s warning to Lombard that, in causing the deaths of Africans, he had murdered men he should understand as his brothers. While both Lombard and Justice Wargrave demonstrate a depraved indifference to the taking of life, Wargrave’s cold, prideful, sadistic glee is such that he goes well beyond Lombard’s mercenary logic to a psychology that suggests the diabolical.

One of Christie’s most famous, most highly praised, and most ingenious novels, And Then There Were None demonstrates darker and more unsettled aspects of Christie’s mystery fiction. There is no romance or recovery at the end of the novel and no pure detective figure who can restore innocence and peace of mind. The novel is instead a study of criminal psychology and of the human personality under pressures of guilt, fear, and anxiety.