I’ve noted previously that Sherlock Holmes works better as a short story than as a novel. A novel is simply too long, so it requires Sherlock to stand around going “Huh?” for most of its length whereas a short story allows him to jump in and solve the case quickly. Since Sherlock’s skills are mostly superhuman, the novel format just doesn’t seem to be as true to the character.
In the first Holmesian novel, A Study In Scarlet, Doyle attempted to solve the problem by having the second entire second half of the book be an elaborate back story in the American West. This was problematic both because it was an abrupt shift in setting, style, and (frankly) quality and because the first half of the novel was still too long for Holmes to not have figured out the case.
This second novel-length work neatly cuts this Gordian Knot by simply removing Holmes from the scene of the action and being a story that largely revolves around the revered Dr. James Watson. Since Watson has always been the viewpoint character, this shift in style allows the mystery to build in a natural way. It also allows Watson to develop as a force of his own. I think he’s been given short shrift up until now, but Hound shows us that he’s been a hero all along.
The story itself was well-paced, entertaining, and interesting. The novel-length allowed Doyle to add a cast of neighbors and servants who wander in and out of the story with varying degrees of suspiciousness. There’s even a butler who may-or-may-not-have-did-it.
All in all, this is an excellent example of the canon and a worthy novel to be considered classic.