
I just got the book. There was a wait list at the library!
Carol ꧁꧂ wrote: "Barb in Maryland wrote: "Carol
All I can think of is 'A Pocket Full of Rye'--one of the Miss Marple stories.
Does this help?"
That does sound like my book! Maybe my thinking it was a Poirot myster..."I'm pretty sure there is also a Poirot where an old, rich man (maybe he owns a factory?) is poisoned by a family member.
And also the old, rich murdered grandfather in
Crooked House, which I think is a standalone.

Dang! That actually sounds like one I have read, but I can't remember which, either!

I'd say start reading Christies until you find it, but that might take years given how prolific she was. Maybe post in the group Carol linked and put whodunnit in spoilers?

I buy that.
Also I can imagine that if you heard something when you were young, read by your parents or that sort of thing, you might unconsciously repeat it in your writing without realizing you'd read or heard it somewhere.

That is a good word! I don't think I've suffered from that, but I've certainly done the other thing, read things written by myself and not remembered them. Including a couple term papers, which really made me wonder. How sleep-deprived was I that semester?!

Indeed. Even now, with text search so easy, publishers sometimes don't catch plagiarism. I suppose the onus is really on the author -- although I don't understand how anyone thinks they'll slide by these days. Maybe some just want the money and don't care about integrity.

Maybe Blue Castle was out of print at the time? Before goodreads I don't think I knew anyone outside of my mother's family who had read it. And they all read the same copy that had belonged to my great-grandmother.
Elinor wrote: "The Blue Castle is excellent, with a plot that is more complex than some of Montgomery's other books. In fact, the plot was copied by Colleen McCullough for her novel [book:The Ladies ..."The plot similarities pretty much spoke for themselves, though.
Abigail wrote: "My favorite go-to when people are annoying me is Miss Melville Regrets by Evelyn Smith. Wish-fulfillment!"Thanks for the rec! I like
The Blue Castle for this mood. Especially the bit where she thinks she's dying and tells off all her relations.
Kavan wrote: "The Vivian reveal as with the twin twist (great phrase for it) went a bit to far for me. Stephenson would be going along with the charming village bit and then all the sudden there were these quasi..."I thought some of these less plausible elements were there to make the plot match more with the way Barbara's novel becomes less realistic as it goes on.

Sure, maybe some more obscure mystery authors, although they may be hard to find. Somewhere in a box I have a reference book that lists them all...