Poirot is flying from Paris back to England, and spends most of the flight sleeping. As the plane nears landing, fellow passenger Madame Giselle, a moneylender, is discovered to be dead. Although a wasp was found in the compartment shortly earlier, Poirot discovers a poisoned dart, and police find a blowpipe next to his seat. He finds himself counted among the suspects, and decides to investigate the case himself, promptly requesting a list of the passengers' possessions, and working with inspectors in both England and France. This results in revelations surrounding Giselle and the other passengers, involving debts, blackmail, a secret marriage and a previously unidentified estranged daughter.
Death in the Clouds was adapted for the television series Poirot in 1992, starring David Suchet. Tropes concerning the adaptation can be found on the page for the series.
This work contains examples of the following tropes:
- Antagonistic Offspring: Anne Morisot hates her mother, Madame Giselle, but looks forward to inheriting. She's more indifferent than outright hostile though, and somewhat justified due to being abandoned as a child.
- Author Avatar: Novelist Daniel Clancy, who loudly complains about how difficult it is to write good stories and how he hates some of his character's tics yet has to keep it because the public loves it.
- Beneath Notice: The murderer is a dentist, but carried out the murder dressed as an airline steward since their clothes look similar.
- Blow Gun: A blowpipe is found next to Poirot's seat in the plane. It turns out to be a Red Herring intended to frame another passenger with whom Poirot had exchanged seats, as the poisoned dart was pressed into the victim by hand.
- The Butler Did It: Giselle was murdered by an air steward - who was actually Norman Gale in disguise.
- Chatty Hairdresser: The story features a hairdresser who has to tell her clients about the murder, over and over again. At least she negotiates a pay rise for it, but eventually she snaps at a particularly bitchy customer and is fired.
- Clear My Name: Poirot finds himself labelled as a suspect, so this forms at least part of his motive for taking on the case.
- Closed Circle: The rear compartment of the plane only had 11 passengers at the time when Madame Giselle died.
- Death in the Clouds: The Trope Namer. Madame Giselle is murdered with a poisoned dart aboard a flight from Paris.
- French Jerk: Very much averted with the Duponds father and son. Poirot ends up matching Jane Grey with Jean Dupond because he's a Nice Guy who will make her forget she fell for a murderer.
- Instrument of Murder: One of the possible solutions suggested is that a flute had been used as a blowgun to launch the dart.
- Love at First Sight: Jane Grey and Norman Gale meet at the casino and are immediately attracted to one another, although they spend more time afterwards getting to know each other.
- The Matchmaker: At the end of the story, Poirot sets up Jane Grey with archaeologist Jean Dupont.
- "No. Just... No" Reaction: The coroner presiding over the murder inquest has the legal equivalent of this reaction when the jury brings in a charge against Poirot.Coroner: What's all this? Nonsense, I can't accept this verdict.
- Reasonable Authority Figure: The presiding judge of the inquest, who shoots down a bigoted attempt to accuse Poirot of the murder by the coroners jury.
- Red Herring: Several other items that share a similar form as a blowpipe (pipe stems, a flute, a cigarette holder) are mentioned, shortly before they figure out the thorn was inserted by hand.
- Spanner in the Works: From the murderer's perspective, the fact that Poirot changed seats with intended scapegoat Countess Horbury during the flight. Similarly, the fact that Lady Horbury impulsively took her maid along in the plane rather than make her take the train.
- Stealth Insult: Poirot muses bitterly that his travel sickness causes his mental capacity to be reduced to below the human average while travelling, and then immediately segues into asking after his rival from The Murder on the Links.Poirot: When the mal de mer seizes me, I, Hercule Poirot, am a creature with no gray cells, no order, no method - a mere member of the human race somewhat below average intelligence! It is deplorable, but there it is! And talking of these matters, how is my excellent friend Giraud?
- Take That!: Daniel Clancy, who writes detective fiction, says that the Sherlock Holmes stories are overrated and filled with logical fallacies.
- Til Murder Do Us Part: The killer married and murdered Anne Morisot for her inheritance money.
- Trademark Favourite Food: Parodied; novelist Daniel Clancy mentions that his own detective creation is always eating bananas, both because he did it once and the fans liked it, and also because that's something the author himself does.
- Two Aliases, One Character: Norman is Mr. Richards, the husband of Giselle's daughter.
- Villainous Breakdown: The murderer has quite a dramatic one after being unmasked by Poirot.
- Wrong Guy First: Jane Grey spends most of the story unaware that her boyfriend is the murderer. Fortunately, Poirot finds a more suitable match for her in Jean Dupont.
- You Just Told Me: During the Summation Gathering, Poirot traps the killer this way:Poirot: You left your fingerprints on the bottle.Murderer: You lie! I wore (trailing off, realising what he just said)Poirot: Ah, you wore gloves? I think, monsieur, that little admission cooks your gander.