What happens
Captain Tex Bradford has swum beyond the fog and gas rings around Magic Island to release a pigeon to Johnson's boat, while the Gregory yacht is drawn into the island's submarine lock. Mrs. Gregory, Joan and Jerry wait anxiously aboard as the water is pumped out and the mast breaks. G-47 appears in the lock, hinting at a demonstration in the control chamber and at a coming fleet. The episode is part of the Magic Island series, and the rest of the story continues beyond this point.
Magic Island, a submerging island with submarine locks, and the Gregory yacht inside a lock between its piers
Characters: Captain Tex Bradford, Mrs. Gregory, Joan, Jerry, G-47
Listen for: Tex has released the pigeon to Johnson's boat, and G-47 calls the group to a demonstration once the island is submerged.
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.