When drug cartels begin vandalizing ancient Aztec sites throughout Mexico in search of the sacred obsidian knife of Aztec emperor Ahuitzotl, the Mexican government reaches out to the U.S. State Department for assistance. Dr. Jon Barrett, an archaeologist and pre-Columbian weapons expert, then journeys to Cuernavaca with his wife Susanna at the request of Eric Winwood, a high-ranking State Department official, to find and rescue the knife before the...