What happens
Captain Bradford, Jerry Hall, and G-47 are trapped in a flooded passage beneath the sea in the Euclidean city, and Mrs. Gregory and Joan wait anxiously for news of them. The Euclidean master builder Kiaps leads the women to a control room where they watch projected images of the surface, showing rescue ships sailing away from the volcanic area. Through the same projections, they see the trapped men in the flooded corridor, pressed near the ceiling. Kiaps explains that the porous steel ceiling lets air pass at a safe pressure, and the water begins to recede. Kiaps also discusses the history of the Great Pyramid, while the men are freed and join the others.
The Euclidean city beneath the sea, including a cavern, a flooded passage, and a control room that projects images of the surface.
Characters: Mrs. Gregory, Joan, Captain Bradford, Jerry Hall, G-47, Kiaps
Listen for: Kiaps explaining the porous ceiling that keeps the trapped men alive, and Jerry's account of their escape.
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.