Servant Of The Underworld by Aliette de Bodard

A dedicated imperial investigator in an alternate Mesoamerican empire is drawn into a web of ritual murders and political intrigue; as he uncovers links between rival priesthoods, court ambition, and unsettling dealings with the dead, he must navigate dangerous loyalties, ancient magic, and the demands of gods and rulers, forcing painful choices between duty, truth, and survival.

Purchase from Bookshop.org