Tropes in Agatha Christie's novels

Agatha Christie’s reputation as The Queen of Crime was built by the large number of classic motifs that she introduced, or for which she provided the most famous example. Christie built these tropes into what is now considered classic mystery structure: a murder is committed, there are multiple suspects who are all concealing secrets, and the detective gradually uncovers these secrets over the course of the story, discovering the most shocking twists towards the end. At the end, in a Christie hallmark, the detective usually gathers the surviving suspects into one room, explains the course of his or her deductive reasoning, and announces the guilty party.

The following is a list of common plot elements and twist endings, collated with reference to the books themselves, although inevitably some of them could be considered both plot element and twist ending.

Plot elements

Least likely suspect

Perhaps the most common element of the Agatha Christie plot is in fact the twist ending itself, that the suspect who seems least likely to have committed the crime (so much so that that person is sometimes not a major character or even considered to be a suspect by the reader) is the culprit (The Murder of Roger Ackroyd, And Then There Were None, Death in the Clouds, Sad Cypress, Appointment with Death, The Third Floor Flat). The murderer tends to conceal either means, motive or opportunity, or a combination of all three. On occasion Christie deliberately breaks the perceived rules of the murder mystery, having characters — such as children, policemen, the narrator or protagonist, one of the victims, or even all of the suspects — commit the murder(s).

Detective warns murderer

In both Death on the Nile and the short story Triangle at Rhodes Poirot advises the more intelligent culprit before any acts are committed that "there is danger". Poirot seems to be warning a potential victim that he or she might be in some sort of jeopardy, but later Poirot points out that he had warned the person, i.e. of the consequent results of murder (arrest, trial, conviction, hanging), but he was ignored.

Clues hidden in plain sight

In Murder on the Links, Poirot stresses the potential importance of a length of lead pipe that is completely overlooked by a rival detective who only focuses on miniscule miscellanea.

Oddity clue

This is a very common clue to the reader that something specific should be regarded as relevant in the immediate events. In The Mystery of the Spanish Chest, a character seems to remember that there was something odd about a room. Poirot remembers that she is puzzled, and later prompts her to remember that a screen was in the wrong place.

This is also used to heighten suspense as to whether the person concerned will "remember" the crucial item, or, having remembered it, whether they can communicate with the detective before being silenced, as for example in After the Funeral, in which Helen Abernethie is attacked while trying to telephone through information about 'something odd' she has remembered which gives a clear clue as to the killer. The same occurs in Lord Edgware Dies wherein Donald Ross is murdered before he can relay information to Poirot about the bizarre difference between the well-educated Jane Wilkinson he first met and the ignorant fashion plate he has just spent the afternoon with, because, although he doesn't realize it, they were two different women.

Familiarity clue

In many other examples, a person appears familiar for some reason. In her early novels, Christie sometimes uses this to indicate that the person is someone else in disguise, but in her later works the reason for the familiarity is more subtle. Familiarity, especially in the eyes, is often used to foreshadow illegitimate children or hidden family relations, as in Hercule Poirot's Christmas.

Missing elements

In Murder on the Links, Poirot draws the attention of Hastings to footprints in one of two flower beds. Hastings is misled into thinking that Poirot is interested in the footprints, but he is actually interested in their absence from the other bed, where they should have also been found.

This trope – which appears in several different forms throughout her novels – was borrowed by Christie from Arthur Conan Doyle's Silver Blaze, in which Sherlock Holmes refers to “the curious incident of the dog in the night-time”, where the “curious” thing is the fact that the dog did not bark rather than that it did. Christie effectively acknowledges the debt in the tenth chapter of Cards on the Table when her crime novelist character, Ariadne Oliver, explicitly mentions the source. The same reference is also specifically mentioned by Poirot in Murder in the Mews.

Chance remarks

In the first chapter of Lord Edgware Dies, Hastings tells the reader that Poirot has always attributed his solution of this mystery to “a chance remark of a stranger in the street”. (The remark – “If they had just had the sense to ask Ellis right away” – has nothing directly to do with the mystery.) This is just one of many examples when the nature of the mystery is explained by an epiphany in which the detective makes a relevant discovery on the strength of a random occurrence.

Invisible staff

It was Christie's assertion that no one notices who is waiting upon them. In Sparkling Cyanide the murderer dresses as a waiter in order to poison a glass of champagne, while in Death in the Clouds the murderer dresses as a steward aboard an aircraft to do likewise. Three Act Tragedy features a character disguising himself as a butler in order to silence a victim. Miss Marple has the same experience in Miss Marple Tells a Story, in which a second chambermaid is able to enter a hotel suite in full view without being noticed. This is a somewhat contentious trope on Christie's part, but it was also used by G. K. Chesterton in at least two of his Father Brown mysteries (The Invisible Man and The Queer Feet).

In Death on the Nile, the second victim is the mousy, rarely glimpsed maid of the first victim, her wealthy employer. The maid saw something and was threatening to blackmail the killers, who killed her to silence her.

Supposedly unreliable character

In A Murder is Announced, the silly and forgetful Dora Bunner tells Inspector Craddock what one particular character was doing shortly before the murder took place. But because she is so unreliable, everybody believes she was mistaken, but she poses a threat to the murderer and is killed off. In The Mousetrap, victim-to-be Mrs Boyle points out that one character cannot be who he pretends to be, but nobody pays attention since Mrs Boyle is presented as a rather unpleasant woman who complains about everything.

In Crooked House, Brenda Leonides tells the narrator early on in the book that she thinks the character who later turns out to be the murderer might not be quite right in the head. No one pays attention as Brenda herself is the main suspect in the poisoning of her much older and very wealthy husband. In Dead Man's Folly, a seemingly dotty old man claims he came upon a dead body, but his story was never believed except by his granddaughter, both of whom are murdered, separately, to keep the original murder secret.

Final dénouement

Christie is famous for her climactic scenes in which the detective brings together all the surviving suspects and explains the solution to the mystery. Frequently the guilty party breaks down and makes a dramatic confession under pressure. The announcement is invariably long-winded, first discussing the clues and the detective's line of reasoning, before the solution is explained. This is an artificial device but designed to increase suspense and create greater reader engagement.

Concurrent non-lethal criminality

This trope, usually blackmail, occurs often in mysteries. In A Pocket Full of Rye, the "perfect housekeeper", Miss Dove, has been discreetly blackmailing another member of the household, who is innocent but has an explosive secret. The investigating inspector agrees not to make a deal of it once the housekeeper has written him a cheque in the amount she received from the person she was blackmailing. He notes that several homes Miss Dove worked for in the past were burglarised with remarkable efficiency several months after she had departed those employers, and indicates to Miss Dove that they may yet meet again.

Twist endings

Secret identities and impersonation

Another contentious trope used repeatedly in Christie's work is the concealment of identity. In Third Girl, Taken at the Flood, A Murder is Announced, Hercule Poirot's Christmas, One, Two, Buckle My Shoe, and After the Funeral, characters are able to pass themselves off as relatives who have been unseen for considerable periods. In Elephants Can Remember, the identity of the murderer is switched with that of the victim at the victim's own request.

In Murder on the Orient Express, all the suspects are revealed to have been connected with the family of a little girl who was kidnapped and murdered, and whose death they are avenging. All conceal their true identities using phony names or pretending not to be associated with the family.

In Third Girl, a troubled young woman who is being drugged fails to notice that her flatmate is also her rarely visited stepmother. In Murder in Mesopotamia, a woman marries a man without realising that it is actually her former husband. In Why Didn't They Ask Evans?, a man well-known to all the major characters is able to disguise himself as another man equally well-known to the same characters without difficulty until given away by having differently shaped ears. In a number of other cases, relatives are able to conceal themselves as strangers, as in A Murder is Announced and Hercule Poirot's Christmas.

In the short story, The Soul of the Croupier (The Mysterious Mr Quin), in which there is no murder or death, the Countess Czarnova and the casino's croupier, Pierre Vaucher, were married ages ago, and despite her mistreatment and abandonment of him, Vaucher, who recognised her, felt sufficient pity for her in her economic distress that he risked his job as croupier to award her roulette money which she did not win at the expense of Christie regular Mr Satterthwaite, the actual winner, who is quite wealthy. The countess did not recognise Vaucher until he admitted what he had done and why. She then burns the money out of pride.

In the short story, The Voice in the Dark (also from The Mysterious Mr Quin), Lady Stranleigh's sister Beatrice was presumed dead in a ship sinking, but actually survived, albeit without memory due to a head injury, was identified as Alice Clayton, a maid, by her younger sister Barbara (Lady Stranleigh) in order to steal her elder sister's inheritance. Beatrice has recently begun to regain her memory after many years and begins to persecute her sister's daughter (niece), Margery, demanding "Give back what is not yours. Give back what you have stolen." The unhinged "Clayton" kills her sister by drowning her in her bath, and is later found dead herself after the mystery is solved, apparently having died peacefully in her bed from a heart attack.

Impersonation may be for the specific reason of establishing a false motive, as in After the Funeral, where the woman impersonating Cora Lansquenet makes a highly contentious comment at a funeral for Lansquenet's brother about his death, which sets the plot in motion, or to establish an alibi (as in Evil Under the Sun), or to establish a false characteristic of the murderer, such as gender (as in Taken at the Flood and Mrs McGinty's Dead).

A variation on this theme is when someone adopts a secondary identity in order to allow their real identity to disappear mysteriously by 'redirecting attention'. This trope is used in At the Bells and Motley, and in modified form, in Dead Man's Folly.

Tampering with time of death

In several stories, the criminal plays with time, to make it look as though the crime took place when the criminal was elsewhere. In Evil Under the Sun the criminals fake a murder for a time when they both have alibis, then commit it later while the preliminary investigative bustle distracts attention.

In Hercule Poirot's Christmas the murder is committed an hour before it appears to have taken place, at a time when the criminal is elsewhere in front of witnesses.

In the inter-related short stories, The Second Gong and Dead Man's Mirror, the time of murder is also distorted by the killer.

In And Then There Were None, the real murderer fakes (with the assistance of a dupe whom he promptly kills off) his death, thus making it seem he was murdered and couldn't have been the orchestrator of the whole scheme. Other victims' diaries and the killer's carefully crafted notes confirm the false sequence of events, thus confusing the police even further.

In Hickory Dickory Dock, an unwitting accomplice (later killed off by the killer) makes a phone call which is ostensibly from the victim, at a time when the killer is standing in front of Poirot.

In the short story The Plymouth Express, and the novel based upon it, The Mystery of the Blue Train, one of the criminal duo disguises herself as the victim at a train station to create the impression that the victim was still alive when, in fact, she had been killed earlier. Playing with time invariably involves devices such as fake phone calls, gunshots, screams, disguises, people pretending to be dead, and other devices that take advantage of an observer's assumptions.

Murderer plays victim

In Peril at End House, a young woman appears to have been the target of a number of murder attempts, and manages to make the acquaintance of Hercule Poirot. In fact she has arranged these in order to mask her planned murder of a distant cousin, who has the same legal name, an important plot point, revealed at the end of the novel.

Similar devices for masking a real murder were employed in A Murder is Announced and The Mirror Crack'd from Side to Side. Similarly, staged murder attempts, designed to fail and to divert suspicion, also occur in After the Funeral and Crooked House.

In And Then There Were None, the real murderer, in an elaborate but essential red herring, fakes his own murder (with the assistance of a dupe whom he promptly kills off) thus making it seem he was one of the victims, killed off much earlier and couldn't have been responsible for the subsequent murders/deaths.

Viewpoint of the murderer

In The Murder of Roger Ackroyd, the murder has been committed by the seemingly above-board narrator, Dr Sheppard, a physician (and we learn later, a blackmailer) who has injected himself into the investigation by Poirot. Sheppard's recounting of everything is honest and accurate, except for omitting his own actions, until after he is exposed. There is a somewhat similar narrative in Endless Night.

In Crooked House, the killer has left a diary detailing the killings and the reasons. It is found by a relative, who kills the killer in a vehicular murder-suicide, leaving papers explaining everything and enclosing the killer's diary for the novel's heroine, the new mistress of the house, to read in confidence.

In Lord Edgware Dies, shortly before her execution, Jane Wilkinson send Hercule Poirot a lengthy missive from gaol about her crimes, told from her own amoral perspective.

In the original And Then There Were None, the murderer, although he had intended to commit the perfect crime, is driven to write down what happened, how he had planned and carried out everything, due to what he admits is a "pitiful" human need for recognition. He places the missive into a bottle which he throws into the sea. Eventually a trawler picks up the bottle and delivers it to the police, who, as the killer surmised, had not solved the mystery of the ten dead bodies on Indian Island. (In the stage and film versions, the end has been sanitized and rewritten. The killer is still alive at the end and explains it all to the character he believes is the only other living person on the island, pointing out that he has just taken a quick acting poison and the other will be believed guilty of the murders unless he or she does the same. In the end, however, there are two survivors, both innocent, survive and can corroborate what actually happened.)

Killer policemen

In Hercule Poirot's Christmas, the murder has been committed by one of the investigating policemen, who also happens to be one of the victim's illegitimate sons.

In the short story, The Man in the Mist, the investigating policeman, who is also the victim's long-lost husband from decades earlier, commits the murder.

Feigned hatred

In Death on the Nile, the initial suspect, Jacqueline de Bellefort, shot Simon Doyle, her lover, who was apparently "stolen" by wealthy Linnet Ridgeway, although he only married her for her money. Jacqueline and Simon remain lovers and are working together. The shooting of Simon by Jacqueline was carefully staged to not do any real harm, although she is a fine shot, as will become clear later on in the story.

The conspirators in The Mysterious Affair at Styles (in which Poirot appears for the first time) only pretend to hate one another but are, in reality, lovers.

A husband and wife, despite appearances that their marriage is breaking down, are actually teaming up to commit a murder (not their first such collusion, either) in Evil Under the Sun. A similar plot device underpins Endless Night.

Unintentional or unknowing killing via manipulation

In A Pocket Full of Rye, a rather dim-witted maid, who had once been in Miss Marple's employ, is duped (and later killed off) by the true culprit into poisoning her employer by putting what she has been told is "a truth serum" in his marmalade.

Unconnected killings

While it is a common red herring to include unrelated minor crimes like robberies in the stories, in Cat Among the Pigeons, only two of the three killings were carried out by the real murderer. The third (a non-premeditated killing for which the guilty party redeems herself by saving another character's life by forfeiting her own) occurred in between the two murders and happened to mimic the first murder in execution.

False corpses → subsequent murders

In Evil Under the Sun, the body of the victim is apparently discovered by two characters, one of whom, a duped innocent party, goes to fetch the police. The other character, the murderer, however, has only “discovered” the body of his accomplice lying in the sand, and is left free to murder the real victim who is in hiding nearby, with a seemingly perfect alibi established.

In Cards on the Table, the murderer finds his victim sleeping, tells the maid she's dead and then kills her during the resulting confusion.

Premeditation and misleading clues

In Murder on the Links, most of the confusing elements of the crime are discovered to have been part of an elaborate plan by the victim to stage his own death and disappear. It is when he is happened upon by the real murderer that the final elements are added to the puzzle.

Similarly, in The Mystery of the Spanish Chest the victim himself plans to hide in the chest and catch his wife with the man that he suspects of being her lover. The murderer kills him while he is in the chest, resulting in a more complex situation to be solved than might otherwise have arisen.

Double bluff

In The Hollow, Poirot arrives at the scene of a murder in time to see a woman with a gun in her hand standing over the body of her husband, who is bleeding to death from a fresh bullet wound. It turns out at the end of the novel that she did in fact shoot him, but that this fact has subsequently been obfuscated by the other witnesses, all incriminating themselves to try to clear the wronged wife, for whom they feel sympathy. Conversely, in Hickory Dickory Dock, the murderer is incriminated by so many clues that it appears he is being framed, with a lack of obvious motive and a clever false alibi for one of the murders weighing in his favor until the end.

In Lord Edgware Dies, the murderer, Jane Wilkinson, an actress, announces how she would kill a potential victim were she to ever do so, and as part of her plot announces herself openly to the butler but has arranged a clever alibi to make it appear she was framed. In The Murder at the Vicarage, the murderers each confess separately, but are cleared and only much later proved to be in fact guilty. In Towards Zero, the psychopathic murderer fakes two sets of evidence that implicate himself in a brutal murder only to plant a third set of evidence that frames a third party, his ex-wife (whose trial and execution are his true intent); he almost succeeds in this plot.

A variation on this is in Ordeal by Innocence, where the man found guilty for the crime, whose posthumously revealed alibi prompts a reopening of the case, turns out to have arranged the murder after all, though not committed it by his own hand. His accomplice, who was to have cleared him, turned on him for personal reasons and he was executed.

Murderer calls on detective

In a number of stories, the criminal deliberately gets Poirot involved in the case. Of course it is only at the end that we discover this, and along the way it makes the real murderer less of a suspect to the reader. In Lord Edgware Dies, Jane Wilkinson asks Poirot to help her obtain a divorce, despite the fact that Poirot is a Catholic, as he points out to her. He agrees however to speak with her husband, who informs him that he has already agreed and written his wife so. Wilkinson already knows this (but claims she never received the notice when Poirot informs her of her husband's agreement), and is actually trying to prove that she has no motive to kill her husband, which she does do anyway. She also kills two other people who know too much.

In The A.B.C. Murders, the murderer sends letters to Poirot announcing the crimes beforehand, intending to frame an innocent person for the crime. A variation is Peril at End House, in which the murderer did involve Poirot deliberately, but until the end the reader is led to think his involvement was coincidental.

Phony murder

In After the Funeral, a natural death is questioned after someone suggests otherwise. In Murder in the Mews, a woman who is engaged to be married is driven to kill herself due to a blackmailer, and her enraged friend and housemate rearranges the scene to make it appear the woman was murdered, with clues pointing to the blackmailer.

Prevention of murder

In the short story The Wasp's Nest, a variation on this theme is that the murderer has a terminal illness and plans to commit suicide in order to frame an intended victim, but is prevented from doing so.

In The Nemean Lion (one of the Labours of Hercules), Poirot comments to a wealthy industrialist (who has been poisoning his wife) that the man reminds him of another man, in Poirot's native Belgium, who was executed for killing his wife. The industrialist's wife comments to her husband at the end of the story that her tonic tastes far less bitter than it had in recent days.

Protection of the murderer by a third party

In Dead Man's Folly, Amy Folliat has protected her son, "Sir" George Stubbs (real name: James Folliat), a war deserter who killed his wife, Hattie, whom he had married bigamously. As no one had seen the real Hattie, he impersonated her with his real wife (whose real name is never learned) and partner-in-crime. Folliat drowned the elderly boatman who had seen someone burying a body in the woods, and his wife, who has been impersonating Hattie Stubbs, killed the man's granddaughter, whose silence had been paid off briefly with small amounts of money, during the Dead Man's Folly fête.

In At Bertram's Hotel, Bess Sedgwick tells investigators (including Miss Marple) that "she" committed the murder of Michael Gorman, and kills herself in dramatic fashion so as to protect her own daughter, Elvira Blake, the real murderer.

In The Mirror Crack'd from Side to Side, Jason Rudd has always tried to protect his troubled wife, Marina, a film star, who has never fully recovered from the severe trauma of having contracted German measles while pregnant and having her only child born with mental retardation. At the end of the novel Rudd provides the ultimate assistance and protection to his wife, who has killed several people, including the person responsible for her tragedy, who Marina met under rather unique circumstances. Miss Marple, who knows the truth, also hazards an accurate guess as to Marina Rudd's peaceful but unexpected passing in her sleep, but poses no problems for Jason.

In Witness for the Prosecution, Romaine Heilger Vole (called "Christine Vole" in the stage, film and television versions of the play), explains to the Sir Wilfred Robarts, QC, defense attorney for the accused killer, her husband Leonard Vole, how her elaborate machinations engineered his acquittal of the murder of wealthy widow Emily French, which he actually did commit. (Only the original story as written by Christie ends with the guilty party getting away with the crime; the stage, film and televised versions end with a legal acquittal but a lethal falling out between the conspirators, in which some measure of earthly justice is attained.)

Murderer commits suicide

In The Murder of Roger Ackroyd, the murderer, who turns out to be the narrator, is allowed by Poirot to avoid prosecution and scandal to his family, which will inexorably ensue unless the killer elects to end his life before the next morning when Poirot will deliver his report to the police, in this case via a self-administered overdose of medicine, to which, as a physician, he has copious access.

The short stories The Cretan Bull and The Face of Helen both end with the suicide of the murderer, albeit with neither direction nor impediment from other characters.

In And Then There Were None, the killer – who planned the entire scheme after learning he was dying from cancer and had not long to live – the last person alive on Indian Island, shoots himself as planned, albeit using a wire contraption technique designed to make the shooting appear to be murder and maintaining the fiction for the police that he was one of the "ten victims". (The ending is radically different in the stage and film versions of the play.)