Curtain: Poirot's Last Case is a 1975 novel by Agatha Christie, and the final story to feature the detective Hercule Poirot. The novel was written by Christie in the 1940s and locked away, as she was unsure of her own survival during WWII and wanted a proper conclusion for Poirot. She authorised its release shortly before her death.
The novel returns to the same location as The Mysterious Affair at Styles, Poirot's first story. Arthur Hastings, Poirot's Watson from the early days, is at loose ends, feeling adrift after the death of his beloved wife. He happily accepts an invitation from Hercule Poirot for a reunion and comes to Styles Court, which is now run as a hotel, only to find that Poirot is in extremely poor health and is confined to a wheelchair. The elderly and crippled Poirot tells his old friend Arthur Hastings that one of the guests at the house is a serial killer, whom he calls "X", and he must act quickly to thwart the killer of their prey before it is too late...
In 2013, ITV adapted the story for the thirteenth and final season of Poirot. Tropes unique to the adaptation are listed there.
The novel contains examples of the following tropes:
- Absence of Evidence: Poirot uses this to point out the flaw in Hastings' aborted plan to murder Major Allerton (whom Hastings suspects has dark intentions towards Hastings' daughter) by poisoning him, as wiping his fingerprints off the bottle containing the poison he planned to use would have wiped away all the fingerprints on that bottle, making it obvious that someone had killed Allerton and with Hastings the prime suspect.
- Accidental Suicide: Barbara Franklin drinks a cup of poisoned coffee that she had prepared for her husband, due to Hastings rotating the bookcase and unwittingly swapping the coffee cups in the process.
- Acquired Poison Immunity: Hercule Poirot drugs the murderer using his own sleeping pills, which he has been taking for many years. He uses the same gambit as Westley does in The Princess Bride, poisoning both cups while implying that only one cup is poisoned.
- All Girls Want Bad Boys: Discussed when Hastings starts to rant about why women tend to fall for the superficial charms of jerks like Allerton. Poirot deduces that everyone wants to have thrills in their lives in some ways, but because women have less opportunity than men to pursue dangerous hobbies, they fulfill their desire through romance.
- Aloof Dark-Haired Girl: Hastings describes his daughter Judith as tall, with dark hair, and rather detached and unaffectionate.
- Ambiguous Time Period: The book has no specific mentions of the time setting, neither dates nor historical references. Christie wrote the novel during World War II and set it aside, as a pre-planned finale, and no edits were made before it was published in 1975.
- Many references in the novel indicate that it's supposed to be set during World War II or not long thereafter. Hastings met his wife in The Murder on the Links in 1923, and they have four grown children. He refers to being wounded in "the war", which he further explains was "the war" for him even though it "was wiped out now by a second and a more desperate war", which would indicate that the story is set some time after the beginning of World War II (and the word "now" suggests that World War II isn't over yet). He mentions that his daughter Grace married a soldier and is now living in India, which would seem to date the story before Indian independence in 1947.
- However, a random scene has a villager comment on the events of The Mysterious Affair at Styles happening 20 years ago, which would date the story to around 1936 and which makes no sense since this would be around the time of Dumb Witness, Hastings's last appearance before he came Back for the Finale.
- A further problem is that other novels written later in the Poirot series clearly are set much later than this book's presumed 1940s time frame. The Clocks has a Cold War espionage plotline, Third Girl makes references to the 1960s, and the last Poirot novel Christie actually wrote, Elephants Can Remember has a specific reference to the year being 1972 so presumably this book must be set some time after. Since The Mysterious Affair at Styles has Hastings specifically say that he's thirty, if the book is set in the early 1970s he would have to be in his later eighties, and the character is clearly not supposed to be that old.
- Artistic License – Gun Safety: Pointed out by Poirot in his letter to Hastings, saying that a bullet directly to the forehead was a clear signal that Norton could never have committed suicide, but thanks to his Obsessively Organized tendencies, Poirot couldn't help but make the wound symmetrical. He figured someone would notice that clue, but no one did.
- Asshole Victim: Unpleasant characters are easier for Norton to turn people against. Examples include the domestic tyrant Matthew Litchfield, the womanizing Allerton, and Norton himself.
- Aw, Look! They Really Do Love Each Other: At first glance, Mrs. Luttrell is a shrill harpy who bullies her husband, while the colonel is a Henpecked Husband who can only timidly submit to his wife's demand. After Colonel Luttrell accidentally shoots his wife, the others realise that despite their frequent fights, they genuinely love each other.
- Back for the Finale: Hastings. The character had been The Watson for Poirot starting with the first Poirot novel (and first Christie novel), The Mysterious Affair at Styles. Hastings continued to serve as a Watson for most of the early Poirot novels and short stories through Dumb Witness in 1937, but had been dropped after that because Christie realized Poirot didn't need a Watson. However she brought him back for this final Poirot installment, in which the readers learn that Hastings had four children and is now a widower, his wife Dulcie having passed away.
- Bad to the Last Drop: There are multiple observations that Styles is a pretty low-grade hotel, and one of them comes when Hastings describes the coffee there as "an uninteresting muddy fluid" and looks forward to the actually good coffee that Barbara Franklin makes.
- Batman Grabs a Gun: The fact that Stephen Norton can never be tried or connected to the murders that he gets away with puts the lives of the entire UK in danger, leaving it hanging in the balance while Poirot is dying of a heart condition; and he is pushed to the absolute limit so much that he has no other option but to shoot Norton dead in order to stop any more crimes from happening. He could not say whether it was right to kill, but he is sure that it's for the benefit of everyone.
- Beneath Suspicion: None of X's victims can reliably be traced back to X because he has no strong connection with them. It's what makes X such a "perfect criminal", as he could never be legally prosecuted for the murders. Even if he's connected, there's no law against indirectly manipulating people to murder; in the end, a murderer is responsible for their own actions.
- Book Ends: This, the last novel in the Poirot series, is set at a mansion called Styles Court. This was also the setting of the first Poirot novel, The Mysterious Affair at Styles.
- Borrowed Catch Phrase: X invokes Poirot's favorite phrase of "little grey cells".
- Call-Back:
- As the story takes place in Styles Court, where Hastings and Poirot solved their first murder together, there's inevitably numerous references to the events of The Mysterious Affair at Styles.
- Poirot alludes to two previous occasions when he tried and failed to warn a prospective murderer against attempting the crime: "once in Egypt, once elsewhere." The former was obviously Death on the Nile, the latter was most likely the short story Triangle at Rhodes.
- When wondering if there's a financial motive for X's crimes Hastings remembers the Evelyn Carlisle case, presumably Sad Cypress.note
- Calling the Old Man Out: Judith calls Hastings out on interfering in her life.
- Chekhov's Party: The drinks at the Franklins where Mrs Franklin was poisoned. Poirot realizes she was actually the murderer, and was trying to kill her husband. Hastings rotated the table while looking up a crossword answer, which caused a Poisoned Chalice Switcheroo.
- Continuity Nod:
- This Book Ends Series Finale has many references to the first Poirot novel, The Mysterious Affair at Styles.
- Poirot says that twice he has warned a murderer, "once in Egypt, once elsewhere." The former is a reference to Death on the Nile while the latter seems to be a reference to the story "Triangle at Rhodes" from Murder in the Mews.
- Hastings mentions the Evelyn Carlisle case, which was Sad Cypress.note
- Hastings remembers "the ABC crimes", which of course is The ABC Murders.
- Dead Man Writing: Poirot's letter, sent to Captain Hastings four months after the former's death, reveals the identity of the serial killer labeled as "X" (Stephen Norton) and gives a reason why Poirot died, leaving the case seemingly unsolved until now.
- Did Not Think This Through: When Hastings admits his intention to murder Allerton, Poirot furiously tells him all the ways the murder would have pointed to him.
- Distant Finale: Four months later, Hastings receives a Dead Man Writing letter from Poirot's lawyers in which Poirot explains what happened.
- The Dog Was the Mastermind: When the kind and discreet birdwatcher is revealed to be a manipulator who pushes people to commit murder for a sick thrill, it definitely counts.
- Downer Beginning: The book opens with Hastings talking about how his wife had died and he's been left lonely and unhappy. Then he arrives at Styles and finds his old friend Poirot is wheelchair-bound and in very poor health.
- Epilogue Letter: The solution to the murders was revealed by Poirot through a letter delivered to Hastings in the final chapter, 4 months after his death.
- Evil Genius: X brags that he has perfected the technique for which Iago was famous, and Poirot is powerless to stop him. Legally, anyway.
- Exact Eavesdropping: Justified, as Norton intended for the conversation of Luttrell offering them free drinks to be overheard by his wife.
- Face Death with Dignity: Poirot stops taking heart medication after killing Norton and accepts his heart condition in this way as atonement so that he can have a calm, dignified end with hours to spare.
- False Friend: Norton, to several characters.
- Five-Second Foreshadowing: When Hastings visits Poirot in his room and asks how he is, Poirot blithely comments, "Not dead yet!" In fact, he is about to die from the angina attack after he'd killed Norton. He tells Hastings the case is solved, and there are only "loose ends to be tied", meaning his own death.
- Flaw Exploitation: X has modeled himself after Iago, and therefore slips in seemingly innocuous comments and lies to push people to the point of murderous intent.
- Foil: If you ever wanted to see what an evil Poirot looked like, it's Norton. If you get into details, it seems that Stephen Norton is the opposite of Poirot in almost every way:
- Poirot is Belgian, thus in a sense an outsider, Norton is English but considered a sissy by some, a trait seen as unfitting for an English man.
- Poirot possessed an outstanding reputation as a detective in Europe while nobody knows what Norton really does and he appears unnoticeable to everyone who isn't Poirot.
- Although Poirot can act patronizing and arrogant, he is ultimately defined by his sense of justice and moral character and is a matchmaker, while Norton is seen as good company but is in reality a sadist who manipulates people.
- Both Poirot and Norton are very intelligent men with strong egos, but Poirot is a detective with a great sense of justice, while Norton purposefully encourages people to tap into their worst instincts so that they commit murder, who can't possibly be traced back to him.
- While Poirot has a strange habit of coming across cases where one wouldn't expect it, Norton's murders by proxy went actually unresolved precisely because he sets them in motion out of petty hatreds among people who wouldn't have become murderers if not for him.
- Finally, Poirot is considered in-universe one of the most brilliant detectives alive and he notes that Norton is the "perfect criminal", because as far as the law is concerned Norton hasn't done anything wrong.
- In the end the only attribute that isn't a dark mirror to the other's is their intellect and success in their respective field of occupation.
- Foreshadowing: Poirot's usual valet is not with him on the trip to Styles. It's a hint he's not actually wheelchair-bound.
- For the Evulz: Stephen Norton's motivation for his many villainies.
- Godzilla Threshold: Seeing Norton drive Hastings to attempt murder was probably the last straw for Poirot.
- Henpecked Husband: Col. Luttrell, whose wife is something of a harpy who doesn't hesitate to scream at him and humiliate him in front of guests. Later subverted when it's revealed that they really do love each other, and the tensions of their marriage are being caused by the stress of running a guest house and trying to make it pay.Boyd Carrington: And there he is, henpecked and bullied and meek as they make ’em!
- He Who Fights Monsters: Defied by Poirot, who knew he possessed both the ability and the ego to become the very kind of serial killer he was always working to put behind bars. He orchestrates his own death, after having committed murder.
- The Hero Dies: Poirot dies of heart failure near the end of the book.
- Heroic Sacrifice: Poirot shoots Norton dead in an effort to save his friend Hastings and many other innocents from becoming victims to his manipulation for them to kill each other... but does so at the cost of his own religious morals, and eventually his own life, as he stops taking his medicine and allows his heart to stop in atonement.
- Hoist by His Own Petard: Mrs. Franklin drinks the coffee she'd poisoned that was intended for her husband, thanks to Hastings' unwittingly rotating the table.
- Almost happens to Allerton, who discussed how an overdose of his sleeping pills could be deadly. Hastings decides to demonstrate on him.
- Honorary Uncle: Judith Hastings calls Poirot "Uncle Hercule".
- Hunting "Accident": How Col. Luttrell shoots his wife, after Norton subtly goads him into it. She survives, and Poirot later reflects that even as he was pulling the trigger something inside Col. Luttrell made him change his aim so she wouldn't be killed.
- I Did What I Had to Do: Poirot, in his posthumous letter, tells Hastings that he had no other way to stop the killings than to kill Norton, comparing it to when he shot a gunman while serving in the Belgian police.
- Indirect Serial Killer: The villain "Mr. X" (Stephen Norton) possesses a knack for picking up on people's fears and insecurities. Using seemingly innocuous comments, he plays on their emotions and plants ideas in their heads, subtly pushing them into committing murder, apparently just because he enjoys it. He has been responsible for at least five murders in this fashion, and nearly tricks Hercule Poirot's best friend Captain Hastings into killing a man he wrongly suspects of having an affair with his daughter (fortunately Poirot intervenes by drugging Hastings' drink, knowing he'll feel different in the morning), as well as managing to goad another man into shooting his wife (she survives) and convincing a woman to poison her husband (by chance, the drinks are swapped and she ends up being the one to die). Poirot, who has figured out what Norton is doing but also knows that he hasn't technically broken any laws, ends up committing a Vigilante Execution in order to stop him — meaning Norton also managed to make Poirot himself a murderer. He then atones for this by allowing his heart condition to kill him.
- Insidious Rumor Mill: Stephen Norton is a sociopath who gets his kicks out of manipulating his peers in genteel society to murder each other, allowing him to get rid of someone with no risk of detection. He does so by making an Innocently Insensitive comment at the right moment to push his victim over the edge and informing others about seeing something he actually didn't.
- Irony:
- Norton's best skill is manipulating people to murder others. His final act is to manipulate Poirot into murdering him.
- In this story, both Poirot and Hastings become murderous and fully intend to kill someone, and both of them do kill someone. For Poirot this person is Norton, but Hastings' intended and actual victims are not the same person: he is goaded into a (fortunately thwarted) murder attempt on Allerton, and he indirectly and unwittingly kills Barbara Franklin.
- It's Personal:
- Hastings does not take Judith's flirtation with Allerton well. Norton exploits this to induce him to poison him.
- The fact that X drove Hastings to murder was probably this trope for Poirot as well. Since Hastings is a well-known close companion of Poirot's, it was almost certainly a knowingly mocking attack on Poirot.
- Karma Houdini: Defied. When X gloats to Poirot that he will never be arrested for his crimes, since he never directly committed the murders himself, and is technically "innocent" under the law, Poirot shoots him dead.
- Karmic Death:
- X is eventually murdered for his crimes.
- Barbara Franklin dies when her attempt to poison her husband backfires, due to Hastings' unwitting intervention when he rotates the bookcase-table to find a book and swaps the coffee cups in the process.
- Knight Templar Parent: Hastings is concerned that Judith might be having an affair with Allerton, a married man, and tries to convince her to leave him. When it doesn't work, he considers poisoning Allerton.
- The Last Dance: Poirot, dying of natural causes and dealing with a murderer he could not bring to justice through proof, kills the man himself and then accelerates his own death by withholding his heart medication.
- Leaning on the Fourth Wall:Hastings: I was tired of this silly joking about my 'speaking countenance'. I could keep a secret as well as anyone. Poirot had always persisted in the humiliating belief that I am a transparent character and that anyone can read what is passing in my mind.
- Love Dodecahedron: Dr and Mrs Franklin are married, but Dr Franklin and Judith Hastings are mutually in love, while Mrs Franklin wants to be with Boyd Carrington, in whom Nurse Craven is also possibly interested, and the latter is also carrying on an affair with Allerton, who is also trying to have a fling with Judith, though she knows what he's doing and is just leading him on.
- Manipulative Bastard: Norton is a doozy of an example, being addicted to the thrill of power he gets from encouraging the worst in others in order to tempt them to murder. He is a Satan figure on par with Iago from Othello and the aliens from The Monsters Are Due on Maple Street.
- The Matchmaker: In his final letter to Hastings, Poirot encourages his friend to marry Elizabeth Cole.
- Meaningful Funeral: After Poirot has died of a heart condition, his funeral is arranged by his friend, Captain Arthur Hastings, and Hastings' daughter Judith, in which Poirot is laid to rest at Styles Court, which is the place where he lived when he moved from Belgium to England as a WWI refugee.
- Miscarriage of Justice: This occurred repeatedly before the beginning of the story, thanks to X's repeated murders by proxy. Poirot manages to avert two further instances of this, firstly by drugging Hastings to stop him from committing murder, and secondly by making sure that Mrs Franklin's death is reported as a suicide. The latter instance is a case of choosing the lesser over the greater miscarriage of justice.
- Murder by Mistake: Hastings turns around a bookcase, inadvertently swapping Mrs Franklin's coffee cup with a poisoned cup she had prepared for her husband.
- Murder Makes You Crazy: Discussed; Poirot lets himself die after killing X because he worries that he might succumb to this and start believing that he has the right to kill those he deemed it necessary to eliminate.
- Murder-Suicide: Poirot allows himself to die by not taking his medication for his heart condition after killing Norton.
- Murder the Hypotenuse: Attempted by Mrs. Franklin. She ends up murdering herself as the hypotenuse herself, as her husband and Judith get married.
- Necessarily Evil: Poirot knows that murder is wrong, but he also knows that killing X the only way he could stop him from continuing his crime.
- Never Suicide: Played straight by Barbara Franklin, whose intended murder of her husband backfired, and Stephen Norton, whose apparent suicide was actually a murder by Poirot himself. Averted by Poirot, unless you get really technical about what counts as suicide.
- Nice Job Fixing It, Villain: X causing the death of Mrs. Franklin sets Dr. Franklin and Judith free to marry.
- No-Sell: Norton's attempt to drive Judith to murder fails; she recognizes the provoking in his actions, and refuses to take the bait.
- Not That Kind of Doctor: Zigzagged with Dr. Franklin. He's a scientist whose field of research is medicine, but he's not a practising physician, and does not deal with patients. Hastings expresses surprise when, after insisting that Poirot see a doctor, the latter requested for Dr. Franklin. Franklin can indeed diagnose the health conditions accurately, but cares too little about human life to be depended on for proper treatment and care.
- Not What It Looks Like: X's modus operandi is making it seem exactly what it looks like.
- Obfuscating Disability: Poirot pretends to be wheelchair-bound, but is in fact still able to walk. This is why he dismissed his usual valet/nurse, and had someone who was kind of a dolt ferrying him around Styles.
- Oblivious Guilt Slinging: Poirot, who is dying, tells Hastings he's always tried to do his best and if God will forgive him. Hastings, not knowing Poirot had murdered Norton, tells him he's always been a good man, "the best a fellow could know".Poirot: My heart bleeds for you, my poor, lonely Hastings.
- Official Couple: Dr. Franklin and Judith gets married by the end of the story.
- One-Word Title: But it does have a subtitle of "Poirot's Last Case".
- O.O.C. Is Serious Business:
- Poirot gives a slanted testimony that will result in Mrs. Franklin's death being ruled suicide, despite knowing he misled with his testimony. At this point, Poirot has decided to kill X and wants any legal complications out of the way. Hastings gives him a What the Hell, Hero? for perjuring himself; Poirot notes he was never under oath and technically didn't perjure himself.
- Hastings himself decides to murder, with Poirot managing to prevent him from a fatally impulsive act.
- Also, Poirot himself, of all people, commits murder.
- Parental Substitute: Hastings states Poirot was a father figure for him.
- The Perfect Crime: Even Poirot calls X the perfect murderer, as he could never be tried, couldn't even be connected to the crimes, and gets away with over six murders. In fact, the only way Poirot could stop him was to kill him.
- Please, Don't Leave Me: Hastings is unhappy to learn Poirot is fine with dying.
- Poisoned Chalice Switcheroo: Used twice. Firstly, Hastings inadvertently swaps Mrs Franklin's cup of coffee with a poisoned one she had prepared for her husband, resulting in her murder attempt backfiring. Secondly, Poirot obliges Norton by swapping around their hot chocolates before drinking; it is immaterial as both are drugged with sleeping pills to which he has developed a tolerance.
- The Power of Love: In a way, the reason why X's plan to manipulate Colonel Luttrell into murdering his wife failed is that, in spite of his anger towards her, he still loves the woman, and deliberately missed shooting her vital parts.
- Pretty Little Headshots: Norton. The headshot turns out to be the clue to the identity of Norton's killer: Poirot himself whose legendary fastidiousness caused him to make an unnecessarily symmetrical headshot.
- Redemption Equals Death: Poirot, when suffering an attack of angina, chooses to grab his crucifix and rosaries instead of his medicine. He had, after all, murdered someone in cold blood, and elected to let God judge him.
- Revealing Cover Up: Hastings wipes his fingerprints from Allerton's bottle of sleeping pills, but Poirot tells him that doing so also removed Allerton's fingerprints. The sudden death of an otherwise healthy man is suspicious enough to trigger an autopsy that would reveal a massive dose of sleeping medication, and a pill bottle with no fingerprints would draw the attention of the police to anybody who considered Allerton an enemy.
- Reverse Psychology: Norton is a master at manipulating people this way. He spies something in his binoculars and makes sure to act like he does not want Hastings to see what he sees. So, naturally, Hastings demands the binoculars.
- Rewatch Bonus: Reading the novel a second time, one can appreciate the clever and subtle ways Norton manipulates people.
- Shadow Archetype: X to Poirot, making for a fitting final case. They are both experts in analyzing people's psyches, but Poirot uses these abilities in the interests of justice while X uses this power to end many lives and wreck many more.
- She Is All Grown Up: A somewhat unsettling passage has Boyd Carrington, who was a friend of Barbara's family when she was a little girl, remember how he gave her piggyback rides when she was a "tiny tot", only to come back years later and find Barbara a 17-year-old "lovely creature."
- Shout-Out to Shakespeare: In-Universe, Poirot compares X to Iago, both master manipulators who drive normally law-abiding respectable people to murder. He even leaves a copy of Othello to Hastings as a clue.
- Shown Their Work: Besides her knowledge of poisons, Christie seems to show off her knowledge of medicines as well. At the time that Curtain was written during World War II, there was no known cure for
angina pectoris
, a sensation of chest pain, pressure, or squeezing, often due to ischemia of the heart muscle from obstruction or spasm of the coronary arteries, most likely due to coronary artery disease. The only known treatments for angina at the time were amyl nitrite (synthesized in 1844 and pioneered for angina treatment in 1867 in the form of poppers, albeit with euphoric side-effects) and nitroglycerin (synthesized in 1847 and pioneered for treatment in 1879, thus superseding amyl nitrite). By the time the novel was published in 1975, however, it becomes Science Marches On, as amyl nitrite poppers were, and are, "very unlikely" to be sold in the UK, since it is illegal under its Medicines Act 1968 to sell them advertised for human consumption; and beta blockers and calcium channel blockers became active as other most common treatments for angina (since they were discovered in the early 1960s). - Sissy Villain: Poirot speculates that it was Norton's resentment at his own "sissiness" and people's reactions to it that drove him to villainy.
- Slain in Their Sleep: Poirot shoots Norton in the head after drugging the latter with sleeping pills.
- The Social Darwinist: Both Judith Hastings and the man she works for, Dr. Franklin, have some extremely disturbing views. A chat about euthanasia of the mentally ill leads Judith to say that people who lead "unfit lives, useless lives" should be killed. Dr. Franklin says "If an imbecile—a cretin—dies, that's a good thing." Hastings for his part can only observe that he'd be reluctant to go to Dr. Franklin for medical care.
- Speech Impediment: Stephen Norton is a severe stutterer. He loses it when speaking to Poirot as he openly admits to being a murderer.
- A Storm Is Coming: A storm comes on the night of the book's violent climax. There are multiple mentions of a disquieted Hastings looking out and watching the clouds roll in.
- Strike Me Down with All of Your Hatred!: One meaning of Norton's smirk when Poirot expresses his decision to kill him.
- Sympathetic Murderer: Poirot himself kills Stephen Norton, in order to prevent him from continuing his string of murders-by-proxy, a string which nearly turned Hastings into one of Norton's dupes. After killing Norton, Poirot lets himself die by not taking his medication.
- Terminally-Ill Criminal: Poirot himself commits murder to remove a sociopath capable of inciting people to murder for his own sick amusement, and his confession only comes to Hastings after his death of natural causes (that is, not taking the medicine for his heart condition).
- This Is Unforgivable!: What finally spurs Poirot to take the law into his hands is Norton almost pushing Hastings to murder someone, which would have led to him being convicted and hanged.
- Title Drop: Poirot observes that when Hastings finally discovers the truth about what has been happening at Styles, he might wish he hadn't found out, that instead he might say "Ring down the curtain."
- Treacherous Advisor: Norton, who acts like he's trying to give helpful advice but is instead always trying to goad the person he's speaking to into committing a horrible crime.
- Unintentionally Karmic: Hastings accidentally becomes an instrument of karma when everyone is having coffee in Barbara Franklin's room, and he is momentarily left alone while the others have gone to the balcony to watch shooting stars. To hide his emotion from his daughter, he swings around a rotating bookcase-table, pretending to be looking for a book, unaware that in doing so he has swapped the places of the two cups of coffee on it, one being Mrs Franklin's and the other being a poisoned one she prepared for her husband, which results in her drinking her own poison and dying.
- Unwitting Pawn: X uses his psychological manipulations to drive people to commit murder when they would have, in other circumstances, let their offenders live.
- Vigilante Man: Poirot becomes one in this story, as he has no alternative.
- Villain with Good Publicity: Norton is a quiet and mild-mannered bird watcher whom everyone likes. He is also an "emotional sadist" who likes manipulating people into committing murder.
- The Watson: Hastings, for the first time in a Poirot novel since 1937's Dumb Witness. The decades have not made him any smarter. He comes to the entirely incorrect conclusion that the man Judith wants is Allerton and completely misses the obvious attraction she has for her boss Dr. Franklin. Towards the end Poirot says he'll leave some subtle cues for Hastings and that those should lead Hastings to the truth, but Hastings doesn't get it and Poirot has to also arrange to leave a Dead Man Writing letter behind so that Hastings will finally know what happened and why.
- Well-Intentioned Extremist: Poirot. Realizing that there is no way to stop Norton or hold him to justice, Poirot instead kills him. Understanding he has the capacity for this is part of what makes him "help along" his own death.
- What the Hell, Hero?: Poirot furiously lays out to Hastings how all of the evidence would have pointed back to him, as his intent to murder Allerton wasn't well-thought out.
- "Where Are They Now?" Epilogue: Inverted. In the book's prologue, Hastings briefly outlines the current fate of the former residents of Styles Court: John Cavendish has died, and his widow Mary has moved to Devonshire while Lawrence, Cynthia and their children now live in South Africa.
- Where It All Began: Set at Styles, the location of the first Poirot story.
- White Hair, Black Heart: X has grayish-silver hair, and is a completely sadistic Serial Killer who "kills" others by manipulating other people to commit the dirty work for him.
