What happens
Dr. Simon Marko, a physicist working on a new type of atomic reactor, comes to Mr. X and Mr. Thurston fearing a security leak after a Red courier is shot dead in Strasbourg. Pagan Zerschmidt, an informer, helps trace the courier's route to Lucerne, where a series of suspicious contacts follow. The investigation brings Mr. Thurston to an apartment house at number 60 Holbeinstrasse, where a concierge has been found dead. Herbert Marshall stars as Mr. X in this episode of The Man Called X, first broadcast on December 16, 1950. Clues about a Red messenger and a set of stolen notes pass among the characters as the search continues in Switzerland.
New York City, Strasbourg, and Lucerne, Switzerland, around 1950
Characters: Mr. X, Mr. Thurston, Dr. Simon Marko, Marilyn Marko, Pagan Zerschmidt, Vanya Sabine, Anton Bieber, Inspector Faboyer
Listen for: Pagan Zerschmidt's garbled repeated name and the clue of the words 'pen pal' spoken by the wounded postman
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.