The Seventh Sacrifice — Tali Spencer

Beltran is a peaceful man, but when his Bolivian cousin is brutalized, he seeks out a native sorcerer in a quest for vengeance. He has no way of knowing Katari, the Inca shaman, is an amaru demon, a serpent shifter determined to break an ancient spell. Beltran's desire for black magic gives Katari what he's waited centuries to acquire -- a perfect sacrifice.