At first light on Christmas Day, 1916, Texas Ranger Captain, Jesse Taylor, and his uniformed nephew, 8th Cavalry Lt. Samuel Taylor, West Point class of 1916, enjoy smokes and mugs of hot, strong coffee on the south porch of the two-story Rocking T ranch house. The quiet house is filled with sleeping family, guests from Terlingua, and a wide-awake cook busily preparing a sumptuous holiday meal.
The distant sound of running horses interrupts the Taylors’ quiet conversation. Soon a band of thirty-six mounted bandidos appears between outbuildings and races toward them. Red-shirted Jesús Colorado, a deserter from Pancho Villa's army, brandishes a flashing saber and leads the shooting and shouting intruders.
Jesse tells Samuel to make pistol smoke as he runs into the house shouting an alarm. He soon returns to the porch with his Winchester rifle and helps Samuel disrupt the attack.
When they leave an hour later, the raiders have killed eight people, including women, children, and cowboys, and they have stolen the Rocking T Ranch horses.
The next day the Taylors bury their dead then Jesse leads Samuel and a cowboy posse across the Rio Grande. They have a plan to snuff out some bandido lamps and bring back those horses.