I really got back into SFF with a vengeance over the past 18 months or so, which means that I don't remember exactly who I have to thank for recommending California Bones as something I might like to read...
The book is set in California, but in a version of that state which is separate from the rest of the US and run by the Hierarch and his cronies - they get their power from magic, with the Hierarch being an osteomancer, his magic provided by ingesting the bones of magical creatures. This is not the only kind of magic there is in the world of California Bones, but it's the most powerful, and it's also the magic of one of our main characters, Daniel Blackland, who saw his father be literally eaten by the Hierarch when he was a child. Because the next best thing to eating the bones of magical creatures is eating those who have done so, since the osteomantic magic literally becomes a part of them.
Anyway, cut to a few years later and Daniel is surviving by (mostly) petty larceny, working for his uncle and stealing things to order. They're approached by someone who works for the Hierarch, telling them of a major score to be made and the existence of a sword Daniel's father had been making at the time of his death. This sword is literally made of bits of Daniel (baby teeth, hair and so on) so not only is it a powerful magical artefact in its own right, Daniel is concerned it could be used to control him. Yes, this book is the urban fantasy version of a heist movie with magic.
Meanwhile, our other main character (Gabriel) is a bureaucrat and stumbles across the preparations Daniel is making, which make him conclude that the plan is actually to assassinate the Hierarch and cause the regime to collapse. Throughout the book we're never entirely sure what Gabriel's plans are about, or which way he will jump - he's certainly not a 'good' person, though some of his actions have good effects on the welfare of others (one in particular is literally a life-saver for the character in question, whose name is Max), and his motivations remain uncertain right through to the end of the book.
Anyway, California Bones is an excellent piece of world-building, set in a California where most people travel by water rather than road. The writing is sharp and pacy, making you want to know what will happen next.
If there's one weak point to the book, I'd say that it's a bit of a sausage-fest and that's what stopped me from giving it 5 stars. Our protagonists are male, as are all three main villains and the main supporting characters (Daniel's father, his uncle, Max, one of Daniel's friends) - in contrast, the somewhat fewer female characters are less well-drawn and I'm left wondering why either Daniel or Gabriel couldn't have been female, since I can't see why this wouldn't have worked just as well.
The series continues in Pacific Fire, which is apparently set 10 years after this book - it's on my TBR list anyway...