"The Mystery of the Waxmen" The Adventures of Superman Radio Serial - March 1945
Superman, Jimmy and Lois are all drawn to mysterious North Bay after a note addressed directly to Superman indicates a terrible threat only he can combat. There, the Man of Steel finds an unconscious boy lying in a boat, drifting in the lake without its paddles.
But wait, Superman notices something familiar about the boy - a mask, a yellow cape, a red leather vest with an “R” emblazoned on the chest - he teases it out for an episode, but there’s no doubt in Superman’s mind that this is Robin, the boy assistant to the mysterious Batman.
In the run-up to their own radio show, Batman and Robin were testing the waters - perhaps literally, given the lakeside locale of this story - in an appearance alongside Superman. They’d team up again, but it’s important to remember that - a cameo appearance alongside the Justice Society notwithstanding - at this point, Superman has never before teamed up with another superhero in any medium. The World’s Finest team is taking its first baby steps here on the radio show…
"The Space Shell" The Adventures of Superman Radio Serial - February 1945
Perry White’s extra-terrestrial personal chef, the “rhymester” and former court jester Poco from the now-destroyed Planet Utopia returns - although his lines, thankfully, are few, far between and mercifully brief. The rhyming gimmick gets old in a rush.
His amazing, transparent Space Shell which transported Poco to Earth in the company of his Terran pals is returned to him by the United States government, who remain thankful for his assistance although they couldn’t replicate the secret fuel formula which allowed the impervious, one-ton bubble to traverse boundless light-years in moments.
Poco is able to briefly refuel the machine, however, which acts primarily as a vehicle to get the doggerel-fond alien and his pal Jimmy Olsen to the North Pole. There, they team up with a pair of Eskimo siblings to confound a Nazi plot involving exploding icebergs which target Allied transports across the Arctic.
Superman, of course, helps rout the Nazi plot, although Jimmy (and to give credit where credit is due, Poco, in some small measure) do a pretty decent job of stalling the foreign fascists until the Man of Tomorrow arrives to save the day.
"The Mystery of the Sleeping Beauty" The Adventures of Superman Radio Serial - January - February 1945
Jimmy and Clark embark on an expedition to find the strange, hidden kingdom of a lost foreign beauty, discovering an isolated tropical empire of wonders which hasn’t known violence for dozens of generations - and is therefore, unfortunately, an easy target for ambitious Japanese soldiers who either seek to conquer the hidden land, or destroy it.