What happens
The Shadow, the wealthy crime fighter Lamont Cranston, investigates the disappearance of Eden Day, the daughter of a wealthy family, from her locked house in the Mesa district of the city. Margot Lane, his aide, works with him as several other people have vanished from the same neighborhood without a trace. Searching old city records, the pair finds an abandoned water conduit lying beneath the district, and they begin to suspect a hidden passage is being used. The series is The Mercury Theatre on the Air, first broadcast on August 7, 1938. The lead actors are not named in the transcript, so they are not mentioned here.
A city's Mesa district in the 1930s, with its houses, a public library, and an abandoned underground water conduit
Characters: The Shadow, Lamont Cranston, Margot Lane, Commissioner Weston, Mr. Day, Mrs. Day, Eden Day, Callahan
Listen for: Margot Lane discovering the old water conduit plan and mapping the disappearances above it
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.