Texas Ranger William Sykes, nicknamed "Captain Bonfire," leads a posse in pursuit of Mexican bandits who have hijacked a gold shipment. The lawmen arrive at the Moreno ranch, where the gang leader, known as "the Vulture," has taken refuge with his gang. After convincing the rancher and his pretty daughter Guadalupe, that the Americans are anti-Mexican marauders, the outlaws make their escape. Guadalupe intends to kill William, but she soon realizes her mistake and falls in love with him.