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 agent.