What happens
Captain Bradford, Mrs. Gregory, Jerry Hall and Joan escape from the Magic Island in the stolen Euclidean submarine and race under the sea. Their radio picks up a warning from Euclidea, and they find that they cannot send messages without revealing their position. Joan explains that the Euclidean location beam runs in timed bursts, leaving only ninety-second gaps in which the group can switch their radio to listen for Johnson. They try repeatedly to reach him while Joan manages the timing and the submarine's controls.
Aboard the stolen Euclidean submarine, travelling under the sea after escaping the Magic Island
Characters: Captain Bradford, Mrs. Gregory, Jerry Hall, Joan, Johnson, Tex
Listen for: The ninety-second silences between the Euclidean beam bursts, and the moment Johnson's call finally comes through on the radio
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.