1927 novel by Agatha Christie. Almost immediately after Captain Hastings' return to England on business and to visit his friend Hercule Poirot, an uninvited guest appeared in Poirot's apartment coated from head to foot in dust. The man's gaunt face stared for a moment, then he swayed and fell.
Who was he? Was he suffering from shock or just exhaustion? Above all, what was the significance of the figure 4, scribbled over and over again on a sheet of paper? Poirot finds himself plunged into a world of international intrigue, risking his life to uncover the truth about 'Number Four'.
As you might have seen by the above summary, this particular installment is considered...strange for a Poirot novel. Agatha Christie apparently wrote it on the heels of a divorce and in need of money. Many of the chapters were originally short stories that she tied together with the overall plot.
In 2013, the book was adapted for the thirteenth and final season of Poirot, with a vastly differing plot, due to the screenwriter finding the novel to be "an almost unadaptable mess". Tropes for this adaptation are listed on the series page.
This novel provides examples of:
- Actionized Sequel: This novel is decidedly more action-packed than any other Poirot outing, including an unusually high body count, multiple characters employing disguises, explosions, stun gases, and fainting episodes. Oh, and there's that scene when Poirot and Hastings climb out of an upstairs window down some ivy...that isn't something you see every day in Agatha Christie's works.
- Always Someone Better: Subverted; not even Hercule Poirot's brother Achille is smarter than he is! Because he's nonexistent, for a start.
- The Cameo: Vera Rossakoff's role in the story basically amounts to this.
- Character Tics: Claud Darrell's odd manner of eating bread is one of these. It helps Poirot know if a man he's just met is really the Destroyer.
- Decapitation Strike: Hercule disguises himself as his non-existent brother Achille, in order to trick the titular group into thinking that Hercule is still at large, so that they can be taken out all at once in the planned operation.
- Fainting: A convenient transition between moments quite often is to have Hastings, who's narrating everything, lose consciousness.
- Faking the Dead: Poirot this time, to throw the Big Four off the scent.
- Four Is Death: Literally. Number Four is the Destroyer, the assassin of the group.
- The Ghost: Number One. He stays in China for the duration of the story, though he's clearly masterminding things.
- I Have Your Wife: The Big Four do this to Hastings, promising to release her if he manages to lure Poirot to them. Luckily, Poirot already thought they'd try this and has had her safe and hidden for months now.
- Loads and Loads of Characters: The novel features around 30+ named characters, though most of them are mere plot devices who provides bits and pieces of clues and moves the plot along without having much involvement with the actual case.
- Master of Disguise: Number Four, the Destroyer. He appears in multiple guises throughout the novel.
- Mythical Motifs: Pondered upon by Hastings after Poirot tells him about his possibly fake brother Achille; he wonders about Poirot's mother and her choice in names for her children.
- Never Found the Body: Hinted at with Number Four, whose body was said to be unrecognizable. Nothing ever comes of it, though.
- No One Should Survive That: The Big Four plant a bomb in Poirot's apartment, which explodes while he and Hastings are there. Poirot presumably walks away unscathed (how exactly he survives is unclear, but he let them think it worked). Hastings is hit on the head and loses consciousness, but makes a full recovery relatively quickly. Thank goodness the two remembered to wear their Plot Armor.
- Oddball in the Series: An easy way to explain this novel is "Hercule Poirot hijacks a Bond novel".
- Patchwork Story: Originally a series of short stories that were published in The Sketch before being converted into a novel.
- Precision F-Strike: Hastings is being dangled over the Thames to try to convince him to write a letter to lure Poirot into the hands of the Big Four. His response? "To hell with your letter!"
- Sadistic Choice: Hastings, captured by the Big Four, has one of these forced on him: lure Poirot into our clutches or your wife will die. Not that they have her at all, but he doesn't know that.
- Sequel Escalation: Poirot usually has to solve one or two (though three or more occur in the odd case) murders and capture the suspect(s). Here, he's up against a criminal organization bent on world domination. Yeah.
- Take Over the World: The Big Four's ultimate goal is world domination.
- Undying Loyalty: Hastings is shown to have this towards Poirot in this book a few times, notably being willing to die rather than let him be captured by the Big Four.
- The Watson: Hastings is back to serve as this.
- Worthy Opponent: Poirot considers Li Chang Yen this, though they never meet.
- Yellow Peril: Unfortunately, there's a bit of this. The mastermind of The Big Four is Chinese (although the other three are Caucasian), among other things.