What happens
Dr. George Haven Beecham and his daughter Elsie race to an airport to recover the sacred emerald of the Incas before a group of Indian priests can fly away with it. Reporter Clark Kent, working with Superman, searches for the priests' wrecked autogyro and learns they have been picked up from the water and are heading for Central Airport. Elsie drives through a storm while Superman flies ahead to stop the priests' seaplane before it can leave. The Adventures of Superman is the series, and this episode is from April 12, 1940. The lead role is played by a voice actor named in the transcript as Superman, and the transcript does not name the other cast members.
The coast near Stone House, a coast guard station, and Central Airport during a thunderstorm
Characters: Dr. George Haven Beecham, Elsie Beecham, Clark Kent, Superman
Listen for: Superman's attempt to stop the priests' seaplane in the storm, and the priests' conversation with Dr. Beecham about the emerald
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.