Sweet Silver Blues is the first book in the Garrett P.I. series by Glen Cook. It is both a fantasy and a detective novel. However, it is not a traditional swords and sorcery fantasy, as it focuses more on the tough detective guy being tough and tricky, and on the mystery at hand. It is perhaps a little more in line with a traditional P.I. novel, although we quickly learn that Garrett is smarter, nicer, and less drunk than the traditional gumshoe. He also finds himself in the middle of what can only be described as a quest, in the grand fantasy tradition of traveling the world encountering many wonders.
The story is set in a fantasy world where technology stalled out at about the level of the Roman Empire, and magic hasn't pushed things much farther. It is peopled by a staggering array of magical peoples, including but not limited to humans, trolls, fairies, dwarves, elves (of multiple sorts), brownies, vampires, goblins, gnomes, rat men, shapeshifters, centaurs, unicorns, dragons, various creatures of Mr. Cook's own invention, and all the various crossbreeds that can result from combinations thereof. Aside from whatever natural magic fuels these creatures, usable magic is in short supply, and there are not too many spells and wizards in this book. However, the generations-long war over the magically important silver mines is a central mover of the plot.
The story starts when Garrett is contracted by a gnome-human crossbreed shoemaker to hunt down a mysterious heir to an old army buddy's ill-gotten silver stores. It gets weirder from there. However, I do not mean to give the impression that this is a particularly chaotic or silly book; it is more detailed and complex than one would expect, but not chaotic. It is humorous, but not wacky. It does a great job of relating a dramatic and convoluted plot set in a crowded and well-developed world. It is not something I'd recommend to anyone who was not already a fan of fantasy-type stories, but it is pretty good within that context. And that's basically my review of the book -- it's pretty good, if you like fantasy.
The next book in the series is Bitter Gold Hearts (yes, the titles follow a theme). It has been over six years since I last read the series, but as I recall the latter books are better, and the series can be read out-of-order without getting confusing. And obviously, the series was good enough that I'm reading it again.