Based on an actual Civil War mission, Colonel Marlowe (John Wayne) and Major Kendall (William Holden) are ordered by General Grant to take three regiments 300 miles into enemy territory. They must destroy the railroad line between Newton Station and Vicksburg in hopes of choking off supplies to the South. Marlowe encounters a Southern belle loyal to the enemy, and keeps her in sight throughout the journey so she can't warn the Confederates. Kendall, a Northern surgeon, and the crusty Marlowe have their differences along the way. Action, romance and gory battlefield surgery accompany the army as the mission is completed. John Ford directed this film based on a novel by Harold Sinclair.~ Dan Pavlides, All Movie Guide