Jerry and Joanna Burton, brother and sister from London society, take a country house in idyllic Lymstock so that Jerry can rest from injuries received in a wartime plane crash. Just as they are getting to know some of the town's rather strange inhabitants, they receive an anonymous letter accusing them of being lovers, instead of siblings. They are told that these anonymous "poison pen" letters have been circulating widely around the town, making various accusations that are unpleasant, but inaccurate. The situation takes an ugly turn when a woman commits suicide after receiving a letter, and the police move in to investigate.
One of only two Christie novels in which the American edition substantially differs in content from the original British (the other is the Poirot novel Three Act Tragedy). The American version cuts out much of the incidental description and character development, focussing more tightly on the mystery.
Adapted for TV in 1985 by the BBC and 2006 by ITV.
This work contains examples of:
- Absence of Evidence: Mrs Symmington's poison letter was a plant, and poor Agnes realised that the letter did not come through the letter box.
- Abusive Parents: Of the emotionally abusive kind. Megan's mother and step-father usually ignore her, and it's observed by Jerry Burton and others that Megan's presence upsets what would have been a traditional nuclear family. It is evident that Megan feels this.
- Advertised Extra: Miss Marple herself only has a handful of scenes and doesn't even appear until about the final third of the novel.
- Beautiful All Along: Jerry's frustration at Megan's poor self image and aggressively down-at-heels appearance combined with her wistful expression as she sees him off to London results in him 'going mad' and taking her to his sister's stylist in town. The results rather stun them both.
- Bluffing the Murderer: Turns out to be the only way to catch the very cunning murderer who has succeeded in framing somebody else. Engineered by Miss Marple with Megan as The Bait.
- Brother-Sister Team: Jerry and Joanna Burton.
- Camp Gay: Mr Pye, who is alluded to be gay, is also described as "abnormally feminine," can recognize makeup brand when seeing it on Joanna's face, and is included by the police as a suspect even though they insist, on experience, that the culprit must be female.
- Crouching Moron, Hidden Badass: Dr Griffith is bumbling and awkward when faced with Joanna's bold, flirtatious, big-city personality, and his idea of courting is showing her pictures of diseased internal organs. He impresses the hell out of her when, as she has faked interest in medicine, he takes her along on a difficult case.
- Driving Question: Who is sending these letters? But as Miss Marple points out, this was the wrong question.
- Fair-Play Whodunnit: It is hinted at and implied a couple of times (though only that... this is Agatha Christie, after all) the first is Jerry's reaction to Elsie Holland herself - he's been absolutely oblivious to the fairer sex, to Joanna's disbelief and slight worry. But one look at Elsie (described more or less as the physical embodiment of Helen of Troy, but minus the charisma) and he's shocked back to life. But she's a live-in nanny... for a man who seems completely oblivious to this. More importantly - as the Inspector lampshades and Miss Marple states in her summation - this beautiful, single girl doesn't get an anonymous letter (and in the normal run of this sort of thing, she should have received one of the very first). The only reason for this is that the letter writer cares for her deeply. Given that Elsie is unattached, what reason would a man have for hiding his interest in her, other than he's married? And the nearest available married man is her employer.
- First-Person Peripheral Narrator: Jerry Burton.
- Everyone Is a Suspect: From Jerry's point of view.
- I Choose to Stay: Jerry and Joanna came to Lymstock so that Jerry can recuperate from his injuries. The initial plan was to stay only for 6 months, but both eventually marry and settle down in the village.
- Literary Allusion Title: The title comes from Edward FitzGerald's translation of "The Rubáiyát of Omar Khayyám":The Moving Finger writes, and having writ
Moves on: nor all thy Piety nor Wit
Shall lure it back to cancel half a Line,
Nor all thy Tears wash out a Word of it.
- Little Old Lady Investigates: Obviously, as a Miss Marple novel.
- Love Makes You Evil: Two examples one male, one female.Mr Symmington. Also, to a lesser extent, Miss Griffiths.
- Marry the Nanny: It's revealed that Mr Symmington has been secretly in love with his beautiful nursery governess Elsie Holland, and that he killed his wife in order to marry her.
- Never One Murder: The murderer is caught on his third attempt - fortunately in time. Poor Agnes.
- Never Suicide: Mrs. Symmington commits suicide after receiving a poison pen letter accusing her of adultery. Actually, she was murdered.
- Noodle Incident: in the latter half the of the book, Mrs Dane Calthorp tells Jerry that she's bringing in an expert on murder: enter Miss Marple. But while Reverend and Mrs Calthorp also appear in The Pale Horse, Miss Marple doesn't. So how does Mrs Calthrop know Miss Marple and what she can do? This is especially peculiar, because in all her other novels and short stories, it's very clearly stated how Miss Marple was introduced to all her cases outside St Mary Mead; it's usually by one of her army of godchildren, (who all call her Aunt Jane) someone she knows from a previous case, or her nephew Raymond takes action to put her in the right place or knows someone involved.
- Ripped from the Headlines: In story. Mr Symmington got the idea of poison pen letters from a couple of other publicized cases, as a way to make his wife's murder look like suicide.
- She Cleans Up Nicely: Megan can't believe how attractive she can look with a little effort. Jerry recognizes that the much of the transformation is due to her improved self image.
- The Unfavorite: Megan's mother and step-father have children on their own, and her parents clearly prefer them over her.
- What an Idiot!: The killer has been clearly established to be the one writing the poison pen letters
- You'd expect: People refrain from sending hate-mail
- Instead Amyee just HAD to tell Elsie what a gold digger she was, assuming the killer would be blamed (ignoring among other things the fact that Elsie might not particularly care what the killer thinks of her)
- Unsurprisingly: She is arrested on suspicion of murder
- What Happened to the Mouse?: After Megan's mother is murdered and her stepfather is arrested for the crime, no mention is made of who would take care of her two young half-brothers.
- It is mentioned in-story that she's not quite 21 yet, and is not yet married. By the standards of the time and place, she might not have been deemed a suitable guardian, and custody might have gone to an aunt or uncle of the boys.