So I've listened to a few of these Marple books now and she's not the narrator, and shows up as a consultant almost half way through the novel. Odd way to tell a story, but apparently endemic to the structure of many of the Marple books. Of the ones I've listened to, this and the first one (Murder in the Vicarage) I've enjoyed the best so far. Breezy, well writen entertainment. Off beat, even after all these years. ( )

with all the adaptations going around, it's sometimes hard to remember if you've actually read the book or not

This is a Miss Marple story, though she does turn up late and is hardly in the story at all.

This is a story of Burton (and his sister) taking a house in the coutry after his flying accident. Soon they have received a poison pen letter accusing them of not being brother and sister, and not long after this people start dying. Burton has most of it worked out, even if he doesnt realise it, before Miss Marple arrives and ties everything up into a neat bow.

Once again, a short neat little story and a quick read to while away an afternoon or two ( )

A brother comes to a small country village with his sister to recover from a flying accident, seeking peace and quiet, but finds a town where all is astir from a batch of anonymous hate mail going around. It seems silly to the siblings at first, but when first one then another villager dies, things get serious.

Oh, this is a good one. Told from the point of view of the brother, I didn’t realize it was going to be a Miss Marple mystery until almost the end, when she gets called in by an old friend to help solve the case. I was fumbling around with guesses right up until the end. ( )

The Poison Pen
Review of the William Morrow Kindle eBook edition (2009) of the Dodd, Mead & Co (US) (July 1942) & the Collins Crime Club hardcover (June 1943) originals.

“I don’t mean that kind of an expert. I don’t mean someone who knows about anonymous letters or even about murder. I mean someone who knows people. Don’t you see? We want someone who knows a great deal about wickedness!”
...
“Jane Marple. Look at her well. I tell you, that woman knows more about the different kinds of human wickedness than anyone I’ve ever known.”
“I don’t think you should put it quite like that, dear,” murmured Miss Marple.

A sister and brother, Joanna and Jerry Burton, move to the village of Lymstock while Jerry is recovering from injuries suffered in a plane crash. As the book was released in the midst of World War II, the implication is that it was a war injury, but curiously the war is never mentioned. Soon after arrival they receive a poison pen letter and they quickly discover that most of the villagers are similar victims. The police are stymied to find the culprit. Then one death occurs, an apparent suicide due to a letter, and then a murder as well. The local vicar's wife calls her friend Miss Marple to help get to the bottom of things.

See cover at https://upload.wikimedia.org/wikipedia/en/4/48/The_Moving_Finger_First_Edition_C...
The front cover of the original 1942 Dodd, Mead & Company (US) hardcover edition. Image sourced from Wikipedia by https://www.nytimes.com/2020/10/25/books/best-agatha-christie-books-murder-myste..., Fair use, Link

This was yet another terrific Miss Marple novel, even though she enters late into the plot. Jerry Burton is more the main character for the most part as he meets the various characters while recuperating from his injuries and falls in love in the process. I was completely clueless as to the solution until Miss Marple helps set a trap to catch the culprit.

“Yes, it was dangerous, but we are not put into this world, Mr. Burton, to avoid danger when an innocent fellow-creature’s life is at stake. You understand me?”

Confusion for Completists
The Moving Finger is the 3rd Miss Marple novel. Some lists, including the Goodreads Miss Marple Listopia, count it as Miss Marple #4 as the short story collection The Thirteen Problems (1932) is counted as #1 only because some of those stories appeared in 1927.

Trivia and Links
The Moving Finger was adapted twice for English language television. Both of those are reasonably faithful to the original plot. I did not find any free trailers or postings of either of them, but they are both available on the Britbox streaming service here in Canada.

The first adaptation was as part of the BBC's Miss Marple (1984-1992) series as Season 1 Episodes 4 to 5 in 1985 which starred Joan Hickson as Miss Marple.

The second adaptation was as part of ITV's Agatha Christie’s Marple (2004-2013) reboot series as Season 2 Episode 2 in 2006 which starred Geraldine McEwan as Miss Marple.

There was a French language adaptation for the Les petits meurtres d'Agatha Christie [French: The Little Murders of Agatha Christie] (2009 - ongoing) series. The episode based on The Moving Finger was Season 1 Episode 3 La plume empoisonnée (2009).This series does not feature a Miss Marple character and instead has a police detective and a reporter as the leads. The plots are transplanted to France and are considerably changed from the originals.

There was a Korean language TV adaptation for the Ms. Ma, Nemesis (2018) limited series. There were 32 episodes to this series which adapted several Miss Marple stories, including The Moving Finger as Episode 5, into a modern day plot of an prison escapee who seeks to clear her own name of her daughter’s murder and solves that and other crimes in the process. The lead role was played by Yunjin Kim, best known in English language television from the TV series Lost (2004-2010). ( )

No review - read so long ago that I don't recall it. ( )