This was included in a boxed set of "The Adventures of Superman." If one is not perceptive, he might think it was part of the series. It is not but it fits nicely into the whole thing. Some miners have invaded an underground society where "mole people" live. They are odd looking little guys who really mean no harm. They are merely trying to survive and have been threatened. They could be obliterated because the miners decide to kill any of these creatures that make an appearance. This is a job for Superman as we hear so many times later. He steps forward and challenges anyone who threatens the little guys. If this was an audition for the series, George Reeves did a good job as the benevolent Man of Steel.
Review of Superman and the Mole-Men
