The Phantom Empire is the greatest serial ever made. It was edited from the 245 minute serial into a 70 minute movie titled Radio Ranch or Men with Steel Faces, but the movie version loses much of the camp value of the serial. Also lost is the way the serial cheats with the cliffhangers, letting us think something terrible happened, only to show something different at the beginning of the next chapter, which typically begins with a stirring piece of music, although there is no indication as to who scored it or whether it was original with this serial.
Gene Autry, playing himself, is half-owner of Radio Ranch, where people come to stay as paying guests and from which Autry broadcasts a radio program every day. In the first chapter, after singing a song, he introduces Frankie Baxter (Frankie Darro) and his sister Betsy Baxter (Betsy King Ross), his partner’s children, who head a club for teenagers sponsored by Radio Ranch called National Thunder Riders or Junior Thunder Riders. They tell about how one day they saw a bunch of men with capes and helmets riding horses that sounded like thunder, though they do not know who those men were. Nevertheless, Frankie and Betsy formed the club, the members of which wear capes and helmets modeled after the ones worn by the original Thunder Riders, as they call them. Other teenagers are encouraged to visit the ranch and join the club, or they can start their own local fan club. Then Autry narrates the next installment of a serial within this serial in which the Junior Thunder Riders ride to the rescue to save a man and his wife from a bunch of bandits. You might think that since this is a radio serial, only dialogue and sound effects would be involved, but they actually act out the parts, almost as if it were being filmed, which, I guess, in a way it is.
Meanwhile, a bunch of men fly in by airplane, who we quickly figure are up to no good. One of them, Professor Beetson (Frank Glendon), believes that somewhere underneath Radio Ranch is Murania, populated by descendants of the ancient city of Mu, who moved underground to escape the glaciers a hundred thousand years ago. Beetson believes they will find valuable deposits of radium and secrets that have been lost to the world, technology based on their knowledge of radiation. Their plan is to get rid of Autry, either by killing him or by causing him to miss a broadcast, which will result in the loss of his radio contract. Either way, they figure the ranch will become deserted, giving them the freedom to look for Murania without being disturbed. This plot point leads to several ludicrous situations in which Autry is fleeing from the Thunder Riders or from the scientists, in danger of losing his life, and right in the middle of it all has to worry about getting back to the ranch in time to sing another song.
All this is on the surface. Meanwhile, twenty-five thousand feet below the ranch is Murania, where the original Thunder Riders live, when they are not galloping about on the surface for whatever reason. There are, of course, the expected absurdities in this lost city, such as that everyone speaks English. More interesting is the mixture of ancient and futuristic technology. The Muranians have wireless telephones, and they have television, allowing Queen Tika (Dorothy Christie) to view what is going on anywhere on the planet, mostly in America. They have all sorts of advanced weaponry, such as guided missiles, and yet the guards carry spears. They have robots to perform the manual labor, but the ones that are armed have swords. Moreover, when the Thunder Riders need to enter or leave Murania, they have a robot turn a crank to open the door, instead of simply having the equivalent of a garage-door opener.
Their government seems to be a bit of a mixture as well. As noted, there is a queen who rules over her subjects. However, she refers to one of the wounded soldiers as a “comrade,” a term not normally used in monarchies, but which would have suggested a communist state like the Soviet Union in 1935. And there is reference to the “secret police.” When she watches the television to see what is going on in the world, she is contemptuous of the insanity she witnesses, calling the surface people fools, who are always in a hurry, their lives full of death and suffering. You might think from this that Murania must be an enlightened utopia, but when the captain of the Thunder Riders fails to capture Autry as she commanded, she starts to put him to death for incompetence, but then decides that lashes with a whip will be a better punishment. She wants Autry captured so that she can drive him off Radio Ranch, because she fears that surface people will discover Murania and invade it.
When the captain fails a second time, she commands Lord Argo (Wheeler Oakman) to put him to death in the Lightening Chamber. But once inside, Argo tells the captain that every time someone is supposedly put to death (thirty-seven so far this year), he saves him so he can be part of the rebellion he is planning. The captain agrees to join the rebellion, and so his execution is faked. When Queen Tika, who has people whipped or executed for merely failing to carry out her orders, despite their best efforts, finds out about the rebellion, she cannot understand why people are turning against her. After all, she knows she has been a good queen, because that is what her underlings tell her when they are asked. Later, Betsy says what most of us have been thinking, that Queen Tika reminds us of the one in Alice in Wonderland, always shouting, “Off with his head.”
Meanwhile, back at the ranch, the Junior Thunder Riders have parallels to Murania beyond merely fashioning themselves after the Muranian Thunder Riders. Frankie has a secret laboratory on the second floor of a barn in which he invents gadgets, just as scientists in Murania continue to develop new technology down below. While the Muranians have wireless telephones, the Junior Thunder Riders can be summoned to the secret laboratory with a light bulb moving up through the roof blinking on and off in Morse code. While the Muranians below the surface watch the world on their television, the Junior Thunder Riders watch what is happening on Radio Ranch with a periscope that peeps through that same hole. And just as the Muranians live secretly underground, the Junior Thunder Riders have a secret underground passageway beneath the barn leading out of the side of a hill much as the entrance to Murania leads out the side of a mountain.
And just because these are not enough plot complications, Autry is framed by the scientists for killing his partner, and so in addition to being hunted by Beetson’s gang and the Muranian Thunder Riders, he is also being pursued by the sheriff, with only the Junior Thunder Riders to help him.
Eventually, Autry is captured and brought to Murania, but then escapes. Later, Frankie and Betsy are captured and brought to Murania. To block the path of anyone not authorized to pass by, there is a robot standing off to the side with a sword held erect. When activated by a button on his chest, an infraray tells it if someone is trying to pass, at which point it comes down with its sword. So, when Frankie and Betsy get to that robot, Frankie presses the off button on the robot, and then they go right past him without a problem. That’s Yankee ingenuity for you.
The rebels do not intend to establish a democracy, but rather simply want power, which promises to result in an even more repressive society than the one run by the queen. As a result, Autry and his friends team up with the queen, who aids them in their escape. However, in the course of the rebellion, all of Murania is destroyed by the latest advance in weaponry.
Back on the surface, Beetson confesses to killing Autry’s partner, daring Autry to try to prove it. However, thanks to a piece of equipment Frankie brought back from Murania, the confession is caught on television, and the bad guys are arrested, after which Autry makes it back to the ranch in time for his final broadcast for the season.