What happens
Superman, posing as reporter Clark Kent, is sent to recover blueprints for a radio-controlled mechanical man and to expose the spy Max Heller and the Yellow Mask. Lois Lane follows a lead to a fashionable Metropolis penthouse that Heller is suspected of using as headquarters. Inside, Heller and his associates confront her, and her hidden presence is discovered. When she fails to reappear, cab driver Tony takes Clark Kent to the building, where Kent finds the penthouse apparently empty. The series is The Adventures of Superman, and this part first aired on December 31, 1941.
Metropolis, a fashionable penthouse apartment and the city streets nearby
Characters: Superman, Clark Kent, Lois Lane, Max Heller, The Yellow Mask, Tony
Listen for: Lois Lane's confrontation with Max Heller and the Yellow Mask in the penthouse, and Superman's discovery of the apparently empty apartment
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.