Something strange is happening at this oil well and the workers there are only aware of it when the boss, Bill Corrigan (Walter Reed), starts to close it down, just as they thought they were making great progress by drilling so far under the ground. Two people who are let down by this news are newspaper reporters Clark Kent (George Reeves) and Lois Lane (Phyllis Coates) who have just flown in by plane to cover the story, but reason while they are here they may as well make the best of it. After some coaxing, Corrigan admits to Kent he believes the drilling has gone too far, and has become radioactively dangerous - but that's not all the enterprise has discovered.
Superman had been portrayed on the big screen before, by Kirk Alyn, but in that instance it was a serial rather than a feature film. This was the first official Superman movie, though technically it was a television show that this was effectively the pilot for, a show which would become one of the most successful of the nineteen-fifties as Alyn declined to continue the role and George Reeves took up the mantle instead. It would make Reeves famous and successful - but only as Superman, as he quickly found himself so closely identified with the part that he was never accepted as anything else. For example, his supporting role in From Here to Eternity was cut when audiences laughed.
But Reeves took his new responsibility as a hero to children across the globe seriously, and appreciated that at least he was adored by a section of the public even if Superman began to weigh heavily on his career. He never saw the end of the fifties, as he was found dead in mysterious circumstances at his home in 1959, a conundrum that has never been adequately explained: was it suicide or murder? We shall never know, but the manner of his death has resulted in Reeves carrying an enigma about him that has lasted well after those who were children when he was most celebrated had grown to adulthood, more than a mere footnote as his predecessor had been.
As for this, it was interesting for other reasons too, mainly because of its anti-prejudice theme of a sort that might have got the big guy who fought for truth, justice and the American way labelled as a Communist for his espousal of understanding between the denizens of Planet Earth. The sinned against Mole-Men of the title lived beneath the ground and two of their representatives climb the hole created by the drill to investigate what is happening on the surface, only for the locals, led by Jeff Corey as Benson, to take up arms against them and hunt them down like wild animals, much to Kent/Superman's dismay. In both guises, Supes does his best to bring about a truce between the two factions, recognising that it is basic fear and bigotry that has turned the humans against the hapless visitors.
In fact, the script went pretty far in making it clear to the audience of (presumably) popcorn-throwing kids that tolerance with regard to the races, the nations, any divided parts of society you care to name, was far preferable to lapsing into violence and taking any promise of civilisation down with it. Noble sentiments entirely worthy of Superman, though he would not often back up his philosophy on the subsequent television show where more often he would be battling crooks and gangsters. Yet that was what made this stand out; the Mole-Men themselves may look ridiculous, more like mini-Max Walls than anything impressive as far as the makeup went, but what they represented was more important. Had Superman been battling a space monster, or some Lex Luthor-manufactured robot, it would have been more in keeping with the contemporary character, but the Second World War had not been too far away from the release of this, and it was evident the makers wished to impart an important message. As it was, Reeves had the charm and authority to carry off that during what was in essence a low budget sci-fi flick. Music by Darrell Calker.