What happens
Batman and Robin, known to the crew as Dick Grayson and his companion, are trapped aboard the yacht of Dick's grandfather, Mr. Grayson, far out at sea. Paul Marsh, the secretary, has ordered the crew to fire on them, and Batman's boat has been holed. Alfred has been sent back toward Metropolis to reach Clark Kent. Marsh delivers an ultimatum demanding surrender. Meanwhile Clark Kent and Beanie Martin search the Wayne house for clues to Bruce Wayne's whereabouts, finding a partly blurred water-stained note that mentions a harbor. This is the Adventures of Superman, the 1946 radio serial.
A yacht far out at sea at night, and the Wayne house in Metropolis.
Characters: Batman, Robin, Dick Grayson, Mr. Grayson, Paul Marsh, Captain Skinner, Alfred, Clark Kent
Listen for: Marsh's ultimatum to Batman and Robin, and the clue that Clark Kent finds in the water-stained note.
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.