I actually finished Robert Jackson Bennett's City of Stairs a few days ago, but I was on vacation and trying to type a review on a tablet didn't seem like the best idea ever.
There's a heck of a lot going on in here, and much of the setting details get dumped early on.
Basically, in this world, there is a continent that once upon a time enslaved the island nation of Saypur. However, a man known as the Kaj rose up and slew the gods of the continent, and the roles sort of reversed. Saypur now controls the continent and enforces strict rules about what people are and are not allowed to study under the Worldly Regulations. The theory being that the less the continentals are allowed to display of their now deceased gods, the less they'll attempt to subjugate Saypur again. The continent is still divided into districts based on the Gods that one built them, with Bulikov at the center of it all. Bulikov, once the Seat of the world, remains fairly backwards as compared to other districts. We hear of the Blink, when all the godly miracles vanished, causing much of the continent to contract, and The Plague Years when plagues prevented by the divinities suddenly came roaring back.
As we start forth in this world, we get an idea of how this system works in a trial setting as a Continental merchant defends himself in court against charges of violating the Worldly Regulations by putting a symbol of one of the dead divinities on his door. His trial is interrupted with the news of the murder of Dr. Efrem Pangyui by persons unknown. Dr. Pangyui, of course, being a Saypuri historian with unfettered access to the histories of the divines and their miraculous objects.
Into this hornet's nest walks Shara and her secretary Sigrud. Shara is a descendant of the Kaj, and in service to the Saupuri Ministry of Foreign Affairs. Which is to say, she's a spy. Sigrud, on the other hand comes from a nation that has descended into piracy and lawlessness following the coup of their king.
Shara starts her investigation by getting back involved with an ex-schoolmate of hers, a Bulikovian City Father named Vohannes Votrov who's currently trying to modernize Bulikov, against the wishes of the Restorationists, who want everything back the way it was. Shara and vo have a bit of history together, given they were romantically involved in school, although his interest lay in his own gender for the most part. Vo also wants Saypur to stop oppressing the continent and to invest in it. What follows delves into the relationships between nations, the nature of the divinities, and one whole heck of a lot of fun as some miracles still work, what's left of the divine makes its presence known, and a beast with Hell for its stomach makes an appearance.
Ultimately, the author tips his hand a few chapters early with the solution to one of the major mysteries, but the big one at the center is well hidden until the very end. The cast is well drawn, and as motives become clear, it becomes amusing at how muddy the waters really are in this world.
Much of the book is written in present tense, which becomes less noticeable as the book picks up steam.
I think Goodreads lists at least one more in this series, which I'll have to find before too long. It's well worth picking up if you're into some grnd mystery hiding in a whodunit.