1860, the great Duchess of Parma, Maria Luisa, wants to provide her little state with train tracks, in spite of the opposition she gets from certain noble people.

In 1859, Maria Luisa (Hildegard Kneff), the Grand Duchess of Parma, hires American engineer Clint Farrell (Don Megowan) to build a railroad in the Apuanian Alps. The Austrians see the railroad as a threat to their security so send their best agent, Stella Von Krueger (Chelo Alonso), to seduce Farrell off the project. Under the guise of a saloon proprietor, it isn't long before she has her hooks in Farrell. Meanwhile, some of Farrell's new men are also enemy agents and try to sabotage the railroad at every turn. Impressed with Farrell's bravery and dedication, Stella eventually falls in love with him, but an extremely jealous Maria Luisa reveals Stella's true identity to Farrell and Stella is expelled from the valley.—Larry B.