During the Civil War, Colonel John Marlowe (John Wayne) is tasked with leading a Union cavalry division to raze a Confederate railroad depot. Marlowe faces further challenges as a result of his frequent disagreements with the regiment’s surgeon, Major Henry Kendall (William Holden), and the presence of Miss Hannah Hunter (Constance Towers), a Southern belle who overhears Marlowe’s secret plans and is brought along to prevent her from spreading the word.