In 1917, revolution rocks Mexico, while just across the border, African-American soldiers plunge the U.S. Army into crisis as they rebel against Jim Crow laws at army camps in Houston and Brownsville. Harrison James is caught in this maelstrom of violence when he travels to the Southwest to investigate the mysterious death of his brother who had commanded a company of African-American soldiers. He meets the beautiful Maria Washington, notorious gunrunner and revolutionary wanted on both sides of the border. Their romance sizzles while his list of suspects grows. James is quickly drawn into a seamy underworld of gunrunning and sedition. To unravel the mystery of his brother's death, he must outshoot bandits and outwit the army. They travel deep into Mexico where they meet up with the popular revolutionary folk hero, Pancho Villa, but are betrayed and forced to fight their way back to the border and use newly discovered information to unmask his brother's killer.