Aliens Drama NBC Period Drama Science Fiction

The adventures of a U.S. marshal (Geoffrey Scott) in the Old West who stumbles upon a futuristic underground city run by aliens. "The Secret Empire" was a pastiche of the Gene Autry movie serial The Phantom Empire. Scenes in the futuristic underground city were in color, but scenes in the 19th century wild west on the surface were "in beautiful black and white," tinted brownish. Aired as a segment of "Cliffhangers."