In 1863, a Union outfit is sent behind Confederate lines in Mississippi to destroy enemy railroads but a captive southern belle and the unit's doctor cause frictions within ranks.

Based on the true story of Col. Benjamin H. Grierson. In the Spring of 1863, Grierson left bases in northern Mississippi, taking 1,700 troopers with him. According to Bruce Catton, Grierson "drove through central Mississippi, tearing up railroads and upsetting [Confederate General] Pemberton's troop deployments before reaching Union-held Baton Rouge."—<[email protected]>