This story has always felt like the odd man out for me. For a few reasons I guess - one, because of the strong American link, which just feels odd in a Holmes story - he's not supposed to deal with stuff here in America, he's in Victorian England, darnit!
Two, because he doesn't really succeed. About all we get from him is a tenuous idea of what probably happened, and even that's more knowledge on his part than actual deduction, and a possible karmic justice in the end.
Then again, "Holmes vs. the Ku Klux Klan" is just bizarre in its own right, just a step down from "Holmes vs. Hitler," and the fact that it's canon and not a pastiche is even more mind-warping.
Aside from all that, poor Holmes. No friends but Watson? Owie. I mean, yeah, expected, and I'm sure he doesn't mind it, but still, stated baldly like that...
Oh, and as another note, the start of this story is another one of the little slips that Holmes fans like to poke and prod at - in The Sign of Four, where Watson met his wife, she had no living mother. And yet now she's off on a visit to her mother? Okay then. This is one of the things that have caused people to theorize that Watson was married numerous times, for what it's worth.
Remainder of the schedule.