What happens
Superman, the Man of Steel, investigates as Lois Lane and Jimmy Olsen face execution in the Valley of the Shadows after Lois and Jimmy are sentenced by the Inca Supreme Council. Jimmy blows a police whistle that echoes through the valley, and Superman hears it and flies to the spot. He dives into a whirlpool and pulls the two of them from the water. Afterward, Lois and Jimmy dry their clothes by a fire and plan to help free Harry White and John Craig, who are held in a dungeon beneath the Inca palace. Clark Kent gets the two men out of their cell, leaving straw-stuffed dummies behind in their clothes. This episode is part of the Adventures of Superman radio series and first aired on December 10, 1941.
The Valley of the Shadows and an underground river in the mountains, and the Inca palace and dungeon beneath it
Characters: Superman, Clark Kent, Lois Lane, Jimmy Olsen, Harry White, John Craig, Bronson, Seber
Listen for: Jimmy's police whistle echoing through the valley, and the plan to fool the Incas into believing the captives are dead
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.