What happens
Jerry and Joan, young prisoners on the ninth level of the Euclidean island, have discovered a laboratory where sound is used as a weapon capable of destroying the world's largest building. They become lost in corridors that seem to shift direction, and they find that doors respond to their spoken commands, opening on the word open and closing on the word shut. Jerry and Joan try various doors, unsure which way to go and worried about the captain and the others. Meanwhile Tex and Pat, who have recovered from the sleep ray, leave their cell to search for the young pair. They wander through a six-sided room with doors that will not open, and they begin to suspect that every move is being watched.
The ninth level beneath the surface of the Euclidean island, a maze of corridors and sound-controlled doors
Characters: Jerry, Joan, Tex, Pat, Captain Bradford, G-47
Listen for: Jerry and Joan find the doors respond to voice commands, and the corridors seem to change direction
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.