a splendid yarn. begins in 19th century london when the british empire was at its peak but was also being challenged. and in the middle, out of nowhere, the action shifts to frontier america with some really evil and badass mormon characters who are out to keep all the women to themselves. it is a great police/detective procedural as well as an awesome dystopian action adventure. obviously the two scotland yard policemen are there just to make HOLMES look good and the plot a little more complicated.

i read the penguin annotated version. the exchanges between HOLMES and WATSON were pretty deep. like the stuff about genius being the ability to withstand pain and hardship, darwn and music etc.

i read some SHERLOCK HOLMES as a kid. but dont remember much of it. really liked this one. THE SIGN OF FOUR is next up.

You may like "The Valley of Fear", the last Holmes novel with a similar structure. In VOF, the American gang, the Scowrers are loosely based on the Molly Maguires.

There was a pretty decent film of The Sign of Four done some time in the 80s, starring Ian Richardson as Holmes. I don't know if it's available on DVD or a streaming option.

Hound of the Baskervilles is the only one of those novels I really enjoyed. I'm just not a fan of that 'Part I: Homes stuff; part II: long ass backstory' structure, Valley of Fear being the worst example. Basically a non-Holmes novel with a Holmes short story grafted on to the beginning.

I find Hound of the Baskervilles a little overrated. Holmes worked best in shorter stories.

One critic of Doyle felt that his greatest weakness was in characterizing women and Americans. I tend to agree with his assessment. I love "Hound..." but it's the only novelette that I enjoy. Of the other three, I always felt that "Study..." is the best.

I think Doyle did better with women who were morally compromised - Isadora Klein (despite the serious issues I have with The Three Gables), Irene Adler, Kitty Winter are all very colorful, three-dimensional characters.

The most successful novella, as a Sherlock Holmes story, IMHO is The Sign of Four, because Holmes remains in the story. A Study in Scarlet and The Valley of Fear have that "mystery/back story/conclusion" structure with Holmes absent for most of the second half, and in Hound, there is that large central gap, predominated by Watson's letters, where Holmes is not on the scene. One reason I think there has never been a really successful film of Hound - hard to sell it when Sherlock is absent for much of the tale.
I do think that The Valley of Fear has a very interesting parallel narrative, where the same character (Douglas/Edwards) disappears and then reappears.