What happens
Captain Bradford sends Jerry and Joan onto the strange Isle of Euchlytia, the Magic Island, to infiltrate the island's laboratory and learn what is being done there. Their rescue boat has been captured, and the Gregory yacht is still held captive nearby. Jerry and Joan wander the island's corridors, where they run into Commander S1, who offers to guide them through the lower levels. Commander S1 leads them to a soundproof chamber where they can talk privately, and Jerry reveals the plan: they intend to get into the laboratory when a gas fills the room, then report to the other Euclidians. Joan and Jerry prepare to use soaked cotton to protect themselves from the gas. Series details and the original air date are not given in the transcript.
The Isle of Euchlytia, the Magic Island, a strange island held by the Euclidians, with its elevators, control chambers, laboratories and a soundproof chamber.
Characters: Jerry, Joan, Captain Bradford, Commander S1, Mrs. Gregory, Johnson, G-47
Listen for: Commander S1's offer to guide Jerry and Joan through the island, and her reaction when Jerry reveals the plan to be in the laboratory when the gas fills the room.
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.