Story Skeleton—Murder on the Orient Express

Story structure relates to the psychological appeal of narrative, that which engages readers and builds in them a sense of anticipation—a desire to know what happens next. Our ongoing exploration now delves into mysteries, illustrating yet again the universality of story structure, albeit from a different angle.

 

By David Griffin Brown

The Golden Age of Mystery

Mysteries didn’t just spring into literature fully formed—they evolved through tradition and innovation. Edgar Allan Poe laid the groundwork with The Murders in the Rue Morgue, introducing the locked-room puzzle. Arthur Conan Doyle took up the mantle, building on logical deduction with a brilliant detective who, more often than not, revealed his insights (and some of the most important clues) only after the climax.

By the 1920s and 30s, readers craved more. This period, known as the Golden Age of Mystery, brought puzzle-based narratives into full bloom. Writers like Dorothy L. Sayers, Margery Allingham, and above all, Agatha Christie embraced the challenge of crafting fair-play mysteries in which the reader is given every clue, though there is a healthy dose of misdirection in the mix.

Christie’s innovation wasn’t merely in clever plots but also in psychological architecture. Francis Wyndham once described her work as “animated algebra”—a neat summation of how her stories dare readers to solve an equation buried beneath charming distractions and subtle false leads. At the heart of her success are her two iconic detectives: Hercule Poirot, the meticulous professional, and Miss Marple, the intuitive amateur. While Poirot dazzles with logic and order, Marple charms with empathy and shrewd observation. Both operate within closed-circle settings where the cast is finite, and everyone is a suspect.

The closed-circle mystery, distinct from a locked-door puzzle, amplifies tension through containment. Rather than wondering how a murder was committed in impossible circumstances, readers focus on who among a tight-knit group could be guilty. Christie’s Murder on the Orient Express is a great example of this approach: a snowbound train, a dead man, and twelve passengers, each hiding secrets. The question isn’t just who committed the murder but how the web of motive and opportunity ties them all together.

Suspects All: The Cast of Characters

In less capable hands, a large crowd of suspects can be overwhelming, but Christie makes each one distinct through sharp dialogue, unique mannerisms, and carefully planted contradictions. 

Character List:

• M. Bouc — Poirot’s old friend and director of the Compagnie Internationale de Wagons Lits. He functions as the Watson figure: inquisitive, a little slow on the uptake, and a stand-in for the reader who is equally mystified by the array of clues.
• Dr. Constantine — A coroner traveling on the train, assisting Poirot with medical expertise.
• Samuel Ratchett / Lanfranco Cassetti — The victim; a kidnapper and murderer traveling under a false identity.
• Hector McQueen — Ratchett’s secretary.
• Edward Masterman — Ratchett’s valet.
• Mrs. Hubbard / Linda Arden — A gregarious, overly dramatic American woman.
• Princess Dragomiroff — An elderly Russian princess.
• Hildegarde Schmidt — The princess’s loyal maid.
• Count and Countess Andrenyi — Wealthy travellers who keep to themselves.
• Colonel Arbuthnot — An upright British officer.
• Mary Debenham — A poised and secretive governess.
• Antonio Foscanelli — “The Italian.”
• Greta Ohlsson — A Swedish missionary travelling on her own.
• Cyrus B. Hardman — A private detective from New York.
• Pierre Michel — The train conductor.

And at the center of this intricate puzzle: Hercule Poirot, the fastidious, sharp-eyed Belgian detective with an unfailing commitment to order and truth. He collects details others dismiss and uses them to construct the psychological profile of his culprit—or culprits.

Plot Points

The Detective and His Methods

This is the typical opening stasis in a mystery: we get a glimpse of the detective prior to the case being revealed, a quick introduction into who the detective is and what is particular to their methods.

Poirot is heading to Istanbul for a short vacation, and as he boards the Taurus Express, he meets Lieutenant Dubosc who thanks him for all he has done to save “the honor of the French Army.” Clearly Poirot is a renown detective, such that he has international clients.

We also get an introduction to his keen observation in what turn out to be some early clues when he chances to eavesdrop on Mary Debenham and Colonel Arbuthnot at breakfast.

Preliminary clues:

• Mary Debenham is worried about missing her connection to the Orient Express.
• Poirot overhears her say, “When it’s all over. When it’s behind us…”

The Closed-Circle Scenario

Before the mystery drops, we get acquainted with some of the characters who will be penned in together and thus become possible suspects.

Poirot receives a telegram about another case that calls him back to London, so he arranges passage aboard the Orient Express. It doesn’t leave until the evening, so he meets with his friend (M. Bouc) for dinner. In the restaurant, Poirot observes Samuel Edward Ratchett and Hector McQueen. Not much of a clue here, but certainly a first impression: Poirot immediately dislikes Ratchett and feels he is untrustworthy. 

It turns out there are no first-class cabins left, and of course a fancy detective like Poirot ought to be in first class, but for now his friend arranges for him take the place of a Mr. Harris who hasn’t shown up. As such, he ends up sharing a carriage with Ratchett’s dinner partner, Hector McQueen.

The Orient Express gets underway. The next morning at breakfast, Poirot (and the reader) are introduced to more of the soon-to-be suspect list: thirteen other passengers of various nationalities.

We end this setup stage with a note of foreshadowing. Ratchett comes to Poirot after dinner and offers to pay him for protection: someone is after him and he fears for his life. But Poirot offers him a resounding NOPE. He’s not interested, and besides, he adds, “I do not like your face.”

The Initial Puzzle

The circumstances for the murder—the opening puzzle—come by way of Poirot’s observations and overheard fragments. There isn’t a client knocking on the door with a case to solve, but by the way a number of clues are revealed before the crime, readers already know that something has happened. But note how this delays the inciting incident.

Key clues:

• The Orient Express arrives in Belgrade at 8:45 p.m.
• M. Bouc gives up his compartment so Poirot can move into first class, which puts him directly next to Ratchett’s compartment and two doors down from Mrs. Hubbard.
• Mrs. Hubbard tells Poirot that she’s terrified of Ratchett and that he tried to open the communicating door between their compartments during the previous night.
• Poirot overhears McQueen ask Arbuthnot to come to his compartment later to discuss India.
• Poirot wakes in the night to a loud groan and a ringing bell; the train has stopped.
• He hears the conductor knock on Ratchett’s door; a voice replies in French: “It was nothing. I was wrong.” Poirot notes the time: 12:37 a.m.
• Later, Mrs. Hubbard rings her bell furiously, then reports that someone was inside her compartment.
• Poirot rings his own bell to ask for some water, at which point the conductor tells him that the train has run into a significant snowbank and may be stuck for days.
• When Poirot hears a loud thump in Ratchett’s quarters, he peeks out his door and sees a woman in a scarlet kimono hurrying down the hallway toward the conductor’s station.

Case Accepted

The passengers meet for breakfast with worried conversation about the stuck train, but they do not yet know about what has occurred during the night. Then M. Bouc fills Poirot in: Ratchett has been stabbed to death. There just happens to be a coroner on board (Dr. Constantine) who thinks he must have died between midnight and 2:00 a.m. After reviewing the crime scene, M. Bouc asks Poirot for his help, and the detective gladly accepts. In other words, the inciting incident has dropped. The detective’s narrative goal is established.

Key clues:

• Ratchett was stabbed ten to fifteen times.
• The window to his compartment was open, but there are no tracks in the snow.
•  The door was locked and chained.

The closed-circle scenario is complete! One of the other passengers must be the killer.

The Case Deepens

As noted earlier, in some mysteries, the inciting incident will arrive with “the initial puzzle,” but the detective isn’t yet fully committed. This is a common feature with Sherlock Holmes—he’s not always sure whether mystery is interesting enough to take on. As such, the point of no return will be the moment when the detective realizes that, yes, they have no choice but to accept the case.

Poirot immediately rises to the challenge. There is a killer in their midst, and besides, his friend has asked for his help. However, this is just a mere murder case for a detective of international renown. It’s not that exciting… yet.

That all changes when Poirot starts interviewing the passengers. He soon learns Samuel Ratchett’s true identity: he is actually Lanfranco Cassetti, a famous murderer and extortionist. He kidnapped the three-year-old daughter, Daisy, of a wealthy Wall Street couple, Colonel Armstrong and actress Linda Arden. After the Armstrongs paid a fortune for Daisy’s ransom, the girl was found dead. Although Cassetti was eventually caught, he used his connections and wealth to get off. 

Now that the case aboard the Orient Express is connected to a larger mystery with international notoriety, the stakes for Poirot become significant. This is his point of no return.

Key clues from the first interviews:

• Mary Debenham tells Poirot that Princess Dragomiroff is the most powerful person on the train, but it’s not clear how she knows this.
• McQueen (Ratchett’s secretary) is not at all surprised that his boss has been killed; he had been receiving threatening letters for weeks.
• Poirot reviews one of the letters and concludes that it was written by more than one person.

More clues from the crime scene:

• Some of the stab wounds appear to have happened after Ratchett was already dead.
• Some blows seem to be from a right-handed assailant, others left-handed.
• Some blows are very deep, others superficial.
• There are two kinds of matches in the ashtray: round-stemmed and flat.
• Ratchett’s watch, apparently damaged in the attack, has stopped at 1:15.
• Poirot finds a handkerchief on the floor with an embroidered initial: H.
• He also finds a pipe cleaner on the floor. 
• In the fireplace, he finds a bit of burnt paper that reads, “—member Daisy Armstrong.”

It is this final clue that leads Poirot to the conclusion about Ratchett’s true identity.

Gathering Evidence

Poirot now has the basic facts about the murder as well as a motive. Ratchett’s past crimes are more than enough reason for someone to want to kill him. So the investigation begins in earnest. Poirot must compile the testimonies of everyone aboard, knowing that some of the stories will be false. It will be in the inconsistencies that he uncovers the truth.

Christie structures these interviews as a series of tightly controlled set pieces. Each conversation reveals facts as well as character tensions and evasions. Poirot’s playful yet incisive questioning, combined with the suspects’ efforts to deflect or mislead, turns what could feel like a mountain of data into a dramatic sequence of tension and discovery. We’re not just watching for clues; we’re watching for cracks in the performance.

Pierre Michel: Conductor of the Wagon Lit

• Ratchett asked for his bed to be made up so he could retire soon after dinner.
• McQueen entered Cassetti’s compartment shortly afterward.
• Ratchett’s bell rang at 12:40 a.m. but he sent the conductor away without opening the door.
• He made up McQueen’s bed at around 1:30 a.m. as he had been up visiting with Colonel Arbuthnot.
• The conductor saw no one else apart from a woman in a scarlet kimono with dragons on it.
• He also confirms that the train has been searched to confirm that no assassin is hiding.

Hector McQueen: Ratchett’s Secretary

• McQueen is shocked to learn of his employer’s true identity.
• McQueen’s father was the district attorney for the Armstrong case.
• After dinner, McQueen returned to his compartment to read.
• Later, he visited Colonel Arbuthnot until 2:00 a.m.
• The only other person he saw was a woman in a red silk robe passing through the hallway; he did not see her return.

Edward Henry Masterman: Ratchett’s Valet

• Masterman last saw Ratchett at 9:00 p.m. when he went to his compartment to tidy up and give Ratchett his sleeping draught.
• He said Ratchett did not want to be disturbed until morning and often slept late.
• Masterman is sharing compartment number four with “the Italian.”
• He had no idea about Ratchett’s true identity, but he is aware of the Armstrong case.
• Masterman smokes cigarettes.

Mrs. Hubbard

• Notably, Mrs. Hubbard rushes dramatically into the interview with critical information to convey.
• She claims the murderer, a man, passed through her compartment and woke her up.
• She rang for the conductor and got him to check the lock on the communicating door. Earlier, she had asked Greta Ohlsson to bolt the door for her because the lock was hidden behind her sponge bag so she couldn’t see whether it was locked.
• She also found a button on the floor of her compartment—the same as from the conductor’s uniform.
• She claims not to know the Armstrongs but knows of the case.
• She is not the owner of the scarlet kimono or the handkerchief.

Greta Ohlsson

• Greta was presumably the last to see Ratchett alive, reading in his room, after she mistakenly opened his door thinking it was Mrs. Hubbard’s.
• She confirms that Mrs. Hubbard had her make sure the communicating door was locked.
• She returned to her own room, shared with Mary Debenham, at 10:55 p.m.
• Mary did not leave the room all night.
• She does not have a red kimono.
• She did not have prior knowledge of the Armstrong case.

Pierre Michel: another conductor

• All of his buttons are accounted for.
• He is angry at being questioned and calls for another conductor to confirm his alibi.

Princess Dragomiroff

• She went to her room right after dinner and read until 11:00 p.m.
• At around 12:45, sleepless, she rang for her maid, Hildegarde, who gave her a massage.
• She heard nothing unusual.
• She knows the Armstrong family well—their daughter Sonia is her goddaughter.
• She mentions that there is another Armstrong daughter, younger than Sonia, who went to live with other relatives; the princess does not know her whereabouts.
• Her nightgown is black.

Count and Countess Andrenyi

• The countess is supposed to attend the interview, but the count claims his wife will be of no help.
• They played cards until 11:00 p.m., then slept through the night and heard nothing.
• The count doesn’t know the Armstrong family.
• He provides Poirot with their passports: there is a spot of grease on the countess’ passport: she is Elena Maria Goldenberg, age 20.
• When Poirot insists on speaking to the countess, she confirms the counts story and says she’s never been to America.
• The count smokes cigarettes and cigars.
• The countess’ nightgown is yellow chiffon.

Colonel Arbuthnot

• He recently travelled from India to Syria.
• He says he met Mary Debenham on the previous train ride.
• He says Miss Debenham is a “lady” who would never take part in such a crime.
• In referring to Miss Debenham, he switches between her title and her first name.
• He was up late talking to McQueen about Indian politics.
• The colonel smokes a pipe.
• He recalls a woman passing his doorway who smelled of a sweet perfume.
• He went to bed at 2:45 a.m., at which time he noticed a man peeking out of room number sixteen. 

Cyrus B. Hardman: Private Detective

• This is the man from compartment number sixteen.
• He is posing as a typewriter ribbon salesman but works for a New York detective agency, hired by Ratchett for protection.
• Ratchett told him the man who was after him was small, with dark skin and a “womanish” voice.
• He was keeping watch and saw no stranger in the hallway.
• He was abroad during the Armstrong case and knows little about it.

Antonio Foscanelli

• “The Italian,” it turns out, has lived in America for a decade.
• He knows little of the Armstrong case.
• He sat with Hardman for dinner, then spent the rest of the night in his compartment.
• He smokes cigarettes.

Mary Debenham

• She got up to nothing that evening and went straight to bed.
• She woke at 5:00 a.m. when she sensed the train had stopped.
• When she opened her door, she saw a tall, thin woman in a scarlet kimono with a shingle cap.
• Mary’s nightgown is mauve. Her roommate Greta’s is brown and wool. 
• She says Greta is worried since she was the last known person to see Ratchett alive, and she insists that Greta left for only a few minutes to take Mrs. Hubbard an aspirin.
• She doesn’t seem too bothered about the murder.

Hildegarde Schmidt: Dragomiroff’s Maid

• She slept until she was summoned to give the princess a massage.
• On her way back, she saw a conductor coming out of a room a few doors down from the princess; he nearly ran into her.
• Mrs. Hubbard’s bell was ringing, but the conductor was headed in the opposite direction.
• When Poirot brings in the conductor staff, Hildegarde claims none of them are the man she saw, who was small and dark.
• She is moved to tears by the Armstrong case.
• She does not own the handkerchief, though she hesitates when she says this.

The Final Puzzle Piece

Now that all the interviews are complete, we’ve reached a midpoint of sorts. However, this isn’t a typical mystery midpoint wherein a new obstacle or red herring arises to raise the stakes further. Instead, the investigation gets a flurry of excitement as Mrs. Hubbard runs in shrieking about a bloody knife in her sponge bag. She then promptly faints. 

Poirot and M. Bouc inspect her compartment. The bag in question is hanging from the handle to the communicating door and the bloody knife is on the floor—a knife that could well have been used for the murder. Poirot confirms the door is locked, but in doing so notices that the door bolt is a foot above the handle. Ah ha! An inconsistency in Mrs. Hubbard’s story! She previously suggested her bag was blocking her view of the bolt, which is why she needed Greta to check that it was locked. 

When Mrs. Hubbard returns to her compartment, Poirot gently questions her about this. Again she confirms Greta locked the door for her, but the detective points out that Greta must have merely tried the handle and found it locked, though presumably it was locked from the other side.

This leads them to search the luggage—Mrs. Hubbard’s and that of the other passengers. 

Key clues:

• Colonel Arbuthnot has pipe cleaners like those found in Ratchett’s room.
• Moisture on the nametag on the Countess’ suitcase has smudged her name.
• The scarlet kimono is found—on top of Poirot’s own luggage.
• While Poirot inspects the luggage, Princess Dragomiroff declares that she loved Sonia Armstrong, the mother of the murdered three-year-old.

Testing Theories

All the clues are accounted for. Now the detective must assess which point to the truth and which are deliberate misdirections.

Poirot frames the puzzle for M. Bouc, Dr. Constantine by presenting two possible solutions: (1) an unknown murderer who somehow boarded the train, committed the crime, and escaped into the snow; or (2) a conspiracy, with multiple murderers among the passengers.

The first scenario is nearly impossible given the snowbound train and locked compartments—and Poirot knows it. But by presenting this neat, simple explanation, he challenges his companions (and the readers) to dismiss the easy answer and consider something far more complex. This moment sustains tension and creates a final red herring, allowing Christie to stretch the puzzle to its limit before delivering the true, far more audacious solution.

Several questions remain: Who does the handkerchief belong to? The pipe cleaner? And the kimono? Who was wearing a conductor uniform if not the conductors? And what time did the murder occur?

After reviewing the evidence with the spellbound (and completely confused) M. Bouc and Dr. Constantine, Poirot is ready to level some accusations and draw out some confessions. Many of these revelations come from subtle details: smudged documents, concealed surnames, emotional slips, and connections that only become obvious once all the pieces are arranged.

• The Countess Andrenyi is Helena Goldenberg, daughter of actress Linda Arden and sister of Mrs. Armstrong. Poirot deduces this from the grease-smeared passport (an attempt to conceal her maiden name) and from Princess Dragomiroff’s earlier mention of a missing younger Armstrong daughter.
• Though the handkerchief is labelled H, it does not belong to Helena. The H is actually an N in Cyrillic, for Natalia Dragomiroff.
• Mary Debenham has also concealed her real name. She was Governess Freebody who worked for the Armstrongs.
• Antonio Foscanelli was the Armstrongs’ chauffer.
• Greta Ohlsson was Daisy Armstrongs’ nurse.
• Edward Masterman, who was working as Ratchett’s valet, served with Colonel Armstrong in the War.

The Big Reveal

Poirot has cracked the case. He calls for everyone to assemble in the dining car. Here we get the classic rundown of the clues in the new light of the detective’s final theory. In some mysteries, the detective will first nab the culprit (climax) and then provide the rundown (resolution), but in others the rundown is the point at which the culprit is exposed. In Murder on the Orient Express, this is the climax.

The detective lays out two possible solutions to the murder. The first is simple: an unknown intruder boarded the train, disguised himself in a wagon-lit uniform, committed the murder, and somehow slipped away into the snowy night. It’s a neat solution with no loose ends.

Poirot then proposes a second, far more complex solution: every suspect aboard the Calais coach was involved. Each passenger, with ties to the Armstrong family, took part in executing justice on the man who destroyed their lives. The murder was a collective act—a self-appointed jury delivering the sentence that the courts did not. The motive was not only revenge but closure. Mrs. Hubbard reveals her true identity as Linda Arden, famed actress and grandmother to Daisy Armstrong, and confesses to orchestrating the entire plan.

The Outcome

We have arrived at the resolution. Poirot turns to M. Bouc and Dr. Constantine and leaves the decision in their hands. M. Bouc, swayed by the tragedy and the nobility of their cause, chooses to present the first, fabricated solution to the Yugoslavian police. Poirot agrees. Justice, he recognizes, has already been served. The case is closed.

Whodunit vs Whydunit

We often refer to mysteries as whodunits, but in fact, most modern mysteries are whydunits—a structural feature that Blake Snyder talks about in Save the Cat! 

The surface question may be who committed the crime, but the real hook is why—and more specifically, the revelation that the motive is not what readers were led to believe. This approach allows for greater variation: the surprise isn’t just in who, but in the shifting context that transforms innocuous actions into damning evidence. The culprit might appear blameless until a hidden motive reframes everything.

Whodunits, by contrast, are more restrictive. The culprit must remain hidden despite a clear motive—leading to ever-wilder twists: a murderer who’s an orangutan (Poe), a culprit revealed to be the narrator (Christie in The Murder of Roger Ackroyd), or, as in Murder on the Orient Express, everyone aboard the train.

In Conclusion

A mystery needs structure that controls what the reader knows and when they know it. The timing of each revelation is as important as the information itself. Christie shows that a slow drip of clues, layered with misdirection, keeps readers guessing and engaged. In this novel, the most effective red herrings are collaborative inventions: the supposed stranger in a conductor’s uniform who vanished into the snow, and the mysterious woman in a scarlet kimono seen in the corridor. Both are deliberate distractions, planted by the conspirators to mislead both detective and reader.

Containment is another powerful tool. A limited setting and a defined cast of suspects help focus attention and raise the stakes. The tighter the setting, the more every detail matters. Christie uses the confined train not just to limit suspects, but to force readers into a mental maze where every piece of information could be significant—or could be bait.

But Christie does give readers the opportunity to solve the puzzle before Poirot does. The clues are all present: the connections to the Armstrong household, the forged passport, the staged evidence. The challenge is in seeing past the misdirection. Like Poirot, the reader is invited to sift through contradictions and false leads to piece together the truth.

And finally, motive matters. Whether writing a whodunit or a whydunit, the reasons behind the crime give the story weight. Motive grounds the puzzle in human nature, making the solution not just an answer to a riddle, but a revelation of character—a moment where readers realize who committed the crime and why it made sense for them to do so.

---

David Griffin Brown is an award-winning short fiction writer and co-author of Immersion and Emotion: The Two Pillars of Storytelling and Story Skeleton: The Classics. He holds a BA in anthropology from UVic and an MFA in creative writing from UBC, and his writing has been published in literary magazines such as the Malahat Review and Grain. In 2022, he was the recipient of a New Artist grant from the Canada Council for the Arts. David founded Darling Axe Editing in 2018, and as part of his Book Broker interview series, he has compiled querying advice from over 100 literary agents. He lives in Victoria, Canada, on the traditional territory of the Songhees and Esquimalt Nations.