What happens
Buzz Corey, commander in chief of the Space Patrol, goes to rescue the cadet Happy from a cavern on Neptune. Earlier, Sam Grady, chief agent of Division A of the Interplanetary Express Office, was robbed of a secret package in a room where no robbery should have been possible. Suspicion falls on the criminal Polodor, who appears to project his voice and watch through a hidden device. Corey and Happy trace the trail through a hotel conference room and a janitor's supply room, where they are attacked. Later, Corey learns from a captured accomplice that Polodor may keep prisoners in a remote cavern on Neptune, which Corey then searches in a spacesuit.
Earth, the Terra Hotel and an Express Office, the Space Patrol headquarters, and a remote cavern on the planet Neptune.
Characters: Buzz Corey, Happy, Sam Grady, Polodor, Blanchard, Borchek, Commander Corey
Listen for: Polodor's booming voice coming from a hidden device, and the sounds that echo through the cavern.
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.