What happens
Clark Kent learns that another two million dollars in gold is to be shipped by train from Hawthorne to Metropolis, and he flies there with Jimmy Olsen to ride the train. Separately, Superman investigates a hidden tunnel beside the railroad tracks near a mountain, where he finds a cave holding a freight car and a shortwave radio set, and he confronts a group of armed men. Jimmy boards the train at Hawthorne, where a man named Mr. White has warned that the gold may be in danger. This episode is part six of the serial The Adventures of Superman, first aired on December 6, 1940.
Metropolis and the railroad line between Metropolis and Hawthorne, including a mountain tunnel beside the tracks and the Daily Planet city room
Characters: Superman, Clark Kent, Jimmy Olsen, Mr. Van Doren, Mr. White
Listen for: Superman's confrontation with the armed men inside the mountain cave and Jimmy Olsen boarding the gold train at Hawthorne
Written from the episode itself; it never gives away the ending. Every recording is remastered for the stream: cleaned of rumble, hiss and mains hum (and the old TV whine where we found it), then levelled in two passes to steady broadcast loudness, so one show is never quieter than the next.