This run of episodes encompasses two six-part story-lines. The first involves Incan priests, and the second is about racketeers.
The Emerald of the Incas: Clark Kent is called in to investigate the secretive behaviour of an archaeologist called George Beecham, who has just returned from a dig in South America and is refusing to see his daughter. This one builds the suspense extremely well, even if the conclusion is a little too convenient. It turns out that Beecham has stolen a sacred Incan idol that he believes holds the secret to immortality, and a group of Incan priests are trying to get it back. I had all sorts of reservations about this story, but most of them were answered; Beecham stole the idol, but he intended to return it after he was done; the Incas didn't understand the secret of the idol anymore, so it's not like their source of immortality had been taken away. It's one of the better stories from the radio serial so far.
There are some dodgy racial issues, though. Superman fights Beecham's native servant, who just happens to be a large, monosyllabic black man. Later on the character is likened to an ape, which is seriously not on. But the character is a minor part of the story, and later on he does prove himself to be genuinely heroic, and the others characters are distraught by his death.
I also got to hear Superman beating up a pack of dogs, or rather a voice actor trying to sound like a pack of dogs. It's bizarre.
The Donelli Protection Racket: In this story, Superman must stop a gang of racketeers. This would all be dull and forgettable, except that it's the introduction of Jimmy Olsen. Jimmy's mother owns a candy store, and is one of the businesses being hit by the racketeers. Jimmy is much as you would expect, and comes across well as a character. I can see why they might want to use him again.
Lois Lane appears in this story, mostly as a hostage, but there are three episodes where she is talked about a lot but never seen. She even manages to get kidnapped and escape without ever being heard. I suspect that the producers of the show just didn't want to pay the voice actress for those episodes, but the plot gymnastics they go through to do it are a little odd.
I'm also impressed by the vocal talents of Bud Collyer, who plays Superman. He has two very distinct voices for Clark Kent and Superman, and switches between them effortlessly, sometimes in the space of a single word. He's very good.