What happens
Jerry Gregory and Captain Bradford explore a narrow steel passage beneath the Euclidian city, guided by the young submarine commander, now named Elaine Raleigh, who has been sent to live with their party as punishment for helping them escape. Believing an emergency exit must exist, they climb toward the volcano's peak and find a heavy steel door that opens downward. Beyond it lies a transparent steel chamber near the water's surface, which Captain Bradford recognizes as a floating lock. Jerry and the Captain then discuss whether to threaten the Euclidians or persuade them to surrender, while an approaching figure in the water suggests they may be discovered. The episode is part of the Magic Island series.
A steel tunnel beneath the underwater city of Euclidea, inside a volcanic mountain near the surface of the sea
Characters: Jerry Gregory, Captain Bradford, Elaine Raleigh, Joan, Mrs. Gregory
Listen for: The discovery of the transparent steel lock near the surface and the figure approaching through the water
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.