Captain Gilmore, an African American officer, and Jenkins Craves, an old buffalo soldier with combat experience, make an odd duo. But together they serve one mission. At the height of the Mexican Revolution, they are commanded to transport Lieutenant Calderon and several other Mexican prisoners to make an exchange for American prisoners. The mission should be simple, with the Americans being held in a small town a few days' ride from the pair's location, but as Gilmore soon finds, nothing is simple south of the border. Their team meets a young woman who travels alone to collect the belongings of a relative: a soldier shot dead by Mexican federal soldiers. Gilmore feels the need to protect this woman, so she joins their team. It's a good thing, too, as they are soon attacked by bandits, the Mexican Federal Army, and a variety of no-good turncoats. Despite these hazards, Gilmore and Craves are determined to complete their mission and save American lives ... but who will save them?