Moon Blood and Salt Flowers

In a land the Spanish have wrested from the Incas, llama-herder Amaya was born of moon blood and is viewed as uncanny-but she has a gift which her people find useful: she can see salt flowers, the malevolent flora from the spirit world that grow on moonless nights to devour the souls of unwary humans. When she comes upon Spanish soldiers slain in their sleep by salt flowers, Amaya rescues the lone survivor and brings him back to her village.
Fernando turns her world upside down, and not just because he is handsome and wants to learn her language. He has been sent by the Viceroy to investigate mysterious deaths in the mines of Potosi, the vast silver deposits of which fuel the mighty Spanish empire. Though fascinated by Fernando, Amaya has reason to be wary. The Spanish are not benevolent rulers-and their religion doesn't recognize the spirit world with which Amaya communicates.
The Spanish don't see the danger. Or the salt flowers.