Furious over Major Mosby's successful raids behind Union lines, General Stoughton orders Captain Morrow to locate the source of the Confederates' information. Morrow convinces pretty Ansonia Forde to provide false information to trap Mosby. Forde, however, is a friend of Mosby's and provides him with useful intelligence which leads to the capture of an army paymaster's wagon. Stoughton's men discover her deception and arrest her as a spy. In order to rescue Ansonia, Mosby stages a daring raid in hopes of capturing a suitable prisoner to exchange for the beautiful ...
A crooked sutler, angry at Major Mosby for taking his wagon-load of contraband gunpowder, works with a Union cavalry officer to lure the Confederate raider into a trap with a young orphan as the bait. The orphan, whose father was a Union soldier killed in the war, blames Mosby for his father's death.
Mosby suspects a union spy is reporting on his plans when his command is worsted in a series of battles. When a map found on the body of a Union officer shows his destination was the home of Nellie Smith, a woman known for her friendship to both Union and Confederate soldiers, he suspects he'll find the source of the military information flowing to the Northerners in her household.
Mosby's men capture a Union naval officer, Captain Steven Craig, who was traveling with an army escort. Mosby knew the man before the war because the two men were rivals for the same pretty girl who is now Craig's fiancée. Mosby doesn't believe that Craig would risk traveling through territory the Rangers control just to visit his fiancée, as Craig claims, and tries to learn the real meaning behind his rival's clandestine visit.