In Europe, men were dying in trenches. In Washington, sentiment was growing for war against the Kaiser. And in Mexico, an explosive plot was set in motion by a German agent, a deposed dictator, and an army of murderous rebels. Amidst the chaos of Pancho Villa's revolution, a force of embittered Tejanos has crossed the Rio Grande, burning ranches, killing Texans, and gathering fighters in its wake. For the Germans, the goal was to paralyze America. For a daring Special Agent and a Texas Ranger, the mission was to go deep behind enemy lines and cut out the heart of an astounding conspiracy-before the West was drawn into a bloody war of its own.