When, in 1913, Helen Bierce Cowden, the daughter of the celebrated journalist and author Ambrose Bierce, asks Amos Littlefault-a one-time assistant to the California curmudgeon-to search for her father, who has apparently left his residence in Washington, D.C., to go to the Southwest, perhaps on his way to Mexico for an unexplained purpose, Littlefault feels compelled to oblige.

What he learns, when he locates Bierce in Laredo, Texas, is that Bierce is in the midst of an investigation into a mysterious group of Mexican warriors calling themselves the Jaguar-Knights. What they are planning is nothing less than the resurrection of the ancient Aztec gods of the region, with potentially cataclysmic results.

So begins a thrilling and dangerous adventure, with Bierce, Littlefault, and their companion Juan Romero traversing the entire country of Mexico in a battle to keep the forces of ancient evil at bay. Whether they will succeed in their mission-and live to tell the tale-is anyone's guess.