It’s 1880 in Cheyenne, Wyoming. A group called the Phantom Riders are stealing gold, which gets U.S. Marshal Jim Donner (Geoffrey Scott) on the case. It turns out that these are no ordinary criminals. Instead, they’ve come from an Inner Earth alien city named Chimera.

The plot is lifted from the 1935 Gene Autry singing cowboy movie serial The Phantom Empire. There, Gene fights the Thunder Riders from a subterranean alien city named Murania.

With the series starting with “Chapter 3: Plunge Into Mystery” — Cliffhangers wanted to put people into the middle of the action — Donner is healing from being blasted with one of the Riders weapons. He later saves Maya (Pamela Brull), who is the daughter of Chimera’s overthrown ruler Demeter, with a whip just like Lash LaRue. Now, the city is commanded by her uncle orval (Mark Lenard, who was also Sarek, Spock’s father), a wheelchair riding maniac who wants to take over the world with the mind-controlling Compliatron, which is powered by gold.

There’s also another alien female named Tara (Diane Markoff) who is on the evil side yet has the hots for our hero. I remember being strangely attracted to her as a seven-year-old Sam and not knowing why.

The story expanded to have a greedy mine baron working with the evil side of Chimera, a giant spider, a mine collapse and even spaceships. But sadly, we’d never see these episodes in America. “Chapter 13: Partisans Unchained” and “Chapter 14: Escape to the Stars” would only play in Europe and we wouldn’t even get a compilation movie for The Secret Empire like the other two serials, Stop Susan Williams and The Curse of Dracula, had.

It’s funny because a lot of critics hated this segment, thinking that science fiction and cowboys had no business being in the same story. Maybe they didn’t know about the serial it was based on. Maybe no one was really ready for serials. But if they could have only released this two years later, when Raiders of the Lost Ark came out, this may have been a bigger success than it was.

Thanks to TV Obscurities for their amazing research.