Set in 1916 during General John J. Pershing’s Punitive Expedition, the story takes place along the scorching Texas-Mexico border. Over 100,000 National Guardsmen have been mobilized to defend the United States and hunt down Mexican revolutionary Pancho Villa and his guerrillas. 

Among these forces are six wealthy, highly entitled young men belonging to the Philadelphia Light Horse, an elite military social club reserved for the city's most privileged aristocrats. Shipped off to train at the dusty outpost of Glenn Springs, Texas, these "Dapper Dans" are completely out of their element. Their world collides directly with Lieutenant Stanley Dinkle, a gritty, down-on-his-luck U.S. Cavalryman who has seen better days.