The Killing Moon (The Dreamblood, 1)

The city burned beneath the Dreaming Moon.

In the ancient city-state of Gujaareh, peace is the only law. Upon its rooftops and amongst the shadows of its cobbled streets wait the Gatherers - the keepers of this peace. Priests of the dream-goddess, their duty is to harvest the magic of the sleeping mind and use it to heal, soothe . . . and kill those judged corrupt.

But when a conspiracy blooms within Gujaareh's great temple, Ehiru - the most famous of the city's Gatherers - must question everything he knows. Someone, or something, is murdering dreamers in the goddess' name, stalking its prey both in Gujaareh's alleys and the realm of dreams. Ehiru must now protect the woman he was sent to kill - or watch the city be devoured by war and forbidden magic.
Dreamblood DuologyThe Killing MoonThe Shadowed Sun
For more from N. K. Jemisin, check out:
The Inheritance Trilogy The Hundred Thousand KingdomsThe Broken KingdomsThe Kingdom of Gods
The Inheritance Trilogy (omnibus edition) Shades in Shadow: An Inheritance Triptych (e-only short fiction) The Awakened Kingdom (e-only novella)
The Broken Earth series The Fifth SeasonThe Obelisk Gate