This wasn't, had never been about me. This was about the dead Jaguar warriors and the dying Emperor; about the peasants in their flooded fields; about the myriad small priests who didn't engage in politics, but sought the well-being of their flock. "You have seen the rain," I said softly. "There is a child in Tenochtitlan: a child who is no more a child, but the living embodiment of Tlaloc's will. He seeks to remake the Fifth World in His image." (p. 308)
Year One-Knife, in the Aztec capital Tenochtitlan. Acatl, High Priest of Mictlantecuhtli (the God of Death), is asked to investigate the disappearance (and presumed murder) of an aristocratic priestess. The prime suspect is his own brother, the Jaguar Knight Neutemoc, with whom he has a complicated relationship. And, to aid his investigations, he is given an apprentice: the arrogant young warrior Teomitl, of whom Acatl knows nothing.
Servant of the Underworld immerses the reader from the first page in a culture that is rich, strange and cruel. Magic -- well, religion -- is real, and it is powered by blood. We first encounter Acatl casting a spell: when interrupted by a summons from Ceyaxochitl, the Guardian of the Sacred Precinct, his first thought is to 'quench the flow of blood from my earlobes before the atmosphere of Mictlan [the kingdom of the dead] could overwhelm the shrine. With the disappearance of the living blood, the spell was broken' (p.2).
Acatl is a powerful magician, but rather less adept at the political games that his role demands. He has been promoted suddenly from a minor provincial role to the High Priest of the God of Death, and he's neither comfortable nor happy with the temporal power bestowed upon him. Part of Teomitl's role in the novel is to make Acatl more aware of the walls he's built around himself. Some of the stones in those walls are his drowned father; his warrior brother and his brother's family; his former apprentice, who died attempting a rite beyond his power; the gods who draw him into their machinations and conflicts, old gods against new; his sense of inadequacy, as a man and as a priest.
Servant of the Underworld is the first in a trilogy featuring Acatl, and I'm intrigued to see where the series takes him. There's nothing in the novel that places it in a historical timeline: the author's afterword indicates that it's set around 1480, forty years before the arrival of Cortez and his conquistadors. Yet the world that de Bodard describes has a definite history of its own, with failed harvests, flooding, war; with flower-garlands, feather cloaks, and the constant sacrifices (human and animal) without which the world would end.
It's a culture as alien and unfathomable as anything in SF: an excellent setting for a complex murder mystery, because most readers will be unable to map the characters or their motives -- religious, social, political -- to more familiar tropes. Acatl may be a priest, but he is not comparable to Cadfael or John the Eunuch or Matthew Shardlake (or, haha, Father Brown). The missing priestess had an agenda that would be inconceivable (pun intended) in most historical settings. And the gods are at once unknowable and strangely human -- or, perhaps, so familiar to Acatl that his perception humanises their strangenesses.