Set in Texas and based on a south Texas folk tale, The Headless Horseman is a story about an Irish adventurer in the War with Mexico. The story takes place soon after the war. Louise Poindexter, a beautiful newcomer, is courted by two men - the arrogant and vindictive Cassius Calhoun and the dashing but poor mustanger Maurice Gerald. Calhoun plots to eliminate his rival when tragedy strikes: Louise's brother, the young Henry Poindexter is murdered. All clues point to Maurice Gerald as the assassin. At the same time a headless rider is spotted in the environs of the Poindexter plantation.