In Missouri, a Civil War border state, the leaders of a Union cavalry troop realize that they are being spied on by Jean Selby (Ann Savage), a young woman who comes from a family of rebel sympathizers. The Union men set out to track down the Selby family, and cavalry officer Capt. Fred Raymond (Alan Curtis) ends up finding Jean. But Capt. Raymond and Jean rapidly fall in love, all the while realizing that a romantic relationship would test their loyalties and endanger their lives.