A special thank you to Tigus who steered me towards this particular Miss Silver mystery, as it is by far the best of the three that I've read so far.
The set up for Latter End has been used dozens of times before - Lord of the Manor (Jimmy Latter) marries Lois, a jumped up younger woman slash self-centered floozy who decides to be the new broom that sweeps out the old. She proceeds to throw out the old retainers and impoverished relatives, then gets into a blazing row with the husband after he finds her trying to rekindle an old flame with his cousin, Antony, who is having none of it, realizing that he made a narrow escape indeed, and ends up dead of poison in her Turkish coffee. The suspect list is loooooong, indeed, because everyone had cause to hate Lois. Including Jimmy, he's just too obtuse and taken with her fragile form to figure it out. She was truly awful.
Not Mrs. Boynton from Appointment With Death awful. More like "I'm so pretty and young and everyone should do exactly what I demand otherwise I will get bored and mope around and behave generally like a spoiled child. Oh, and I'm the center of the universe, so no one else's needs are important at all."
Frank Abbott, one of Miss Silver's old pupils who is now the younger half of a Scotland Yard detective team shows up with DI Lamb to investigate the crime. Jimmy, distraught, hires Miss Silver to come to the country house and dig around because he is convinced that the lovely Lois committed suicide because she was upset about the fact that he'd been giving her the silent treatment for two days after he found her practically mauling cousin Antony in her negligee. Did I mention that Jimmy is obtuse? Jimmy is obtuse.
Miss Silver's contribution to the mystery is very Marple-esque - she uses her knowledge of human nature and her sharp eyes to figure out when the various and sundry occupants aren't telling the truth, the whole truth and nothing but the truth and then worms it out of them in the nicest way possible. I am pretty sure at this point that I like Miss Silver more than I like Miss Marple, although continued investigation is required to confirm.
I came up with a solution at 70%, which turned out to be right on. It was a pleasing solution because this is one of those mysteries where the victim is extremely hateable, and everyone else actually seems pretty nice, if a bit dramatic at times.
The Miss Silver mysteries do not seem to need to be read in order, so I'd recommend this one over either of the other two I read.