On a college field trip to caverns near the remote Mexican village of Bustamante, the daughter of a U.S. senator is murdered, the blood drained from her body. Detective Artemas Salcido, a Harvard-educated, illegitimate son of a Mexican governor and a Yaqui Indian girl, is responsible for the investigation. Handsome and cosmopolitan, Artemas was banished to Bustamante because of his ill-advised propensity for solving politically sensitive crimes, and now he finds himself in the middle of yet another.
The international press, two FBI agents, and a brutal squad of federales with orders from the President of Mexico to make the problem go away, descend on the village. Among the reporters is Laffi Rendón, an old flame of Artemas' from Harvard. As more grisly killings occur, Artemas discovers a secret cabal, Grupo Vampiro, which leads him to a labyrinth of rituals and crimes stretching from mediaeval Eastern Europe to Mexico's most powerful people.