Or, from the point of view of foreigners: Gujaareh is a city where these seriously damn scary ninjas sneak in through your window while you're asleep and kill you by sucking your soul out. You will note a certain amount of tension between the views.
The story is split between a pair of death-ninjas and a foreign ambassador (read "spy", of course). There is political tension in the city, which means that all sorts of buried evil and nastiness is about to come to light. Serious nastiness. Remember when vampires were a terrifying devouring force of darkness, before they turned into commonplaces? This portrayal of dream-magic is fresh enough to get back to that. Also, absolutely every side of the conflict is wrong.
The theme is that power corrupts, I guess, and magic is awfully powerful. The author has visited this theme before, of course; the Arameri in her first trilogy were world-class bastards because of their magic. But in those books, the gods got a free pass -- they were exemplars and reflections, but they were supposed to be powerful. That wasn't questioned. In this series, magic is questioned all up one side and down the other: the cost, the ethics, who controls it, who deals with misuse. I seriously wondered, reading, whether the answer would turn out to be "Wow, this was a total frickin' mistake, let's exterminate all knowledge of dream-magic." (Not this book, but I haven't ruled it out for the sequel.)