What happens
Captain Redford, Mrs. Gregory, Joan, Jerry, Pat and Tex escape a stolen Euclidean submarine just off the Los Angeles Harbor at San Pedro, while a rival submarine holds them fast by magnetic beam. Joan works the controls as darkness falls over the Catalina Island Channel. Using escape cylinders, the party rises to the surface one at a time, where Johnson waits with his sailboat to pick them up. Once aboard, they set course for the mainland. Johnson hears the group's account of the Euclideans, the magnetic bombs and the musical notes that threaten their boats, and the episode closes on the group making for shore.
The Los Angeles Harbor at San Pedro and the Catalina Island Channel, at night, aboard a stolen Euclidean submarine and then Johnson's sailboat.
Characters: Captain Redford, Mrs. Gregory, Joan, Jerry, Pat, Tex, Johnson
Listen for: Joan's explanation of the escape cylinders and the magnetic bombs, and the sound of the Euclidean submarine's compressors exploding.
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.