This isn’t a novel but rather a collection of stories, each one a different tale covering the investigation of a mystery by Holmes. They were originally serialised in a magazine, which explains some of the cross and back references (that come across as a bit of self-promotion).
They’re charming enough tales, but a little uncomplicated compared to modern mysteries. To be fair, their length doesn’t allow too much time to build layers and add depth. Instead, most are populated by fixed caricatures and recognisable stereotypes.
They vary in quality, with some being better than others — developing more naturally and having some actual investigation — rather than simply being dictated for Holmes to provide an answer without leaving his rooms.
Some are less a mystery than others, with the answer being easy enough to guess at.
Another Librivox recording, this time by Mark Smith, who does an excellent job, altering his voice to inhabit each character and, despite being an American, doing well with quintessentially British fare.
An entertaining, if not particularly challenging read.