"The Man Called X" was a popular espionage and adventure radio drama that aired on CBS and NBC from July 10, 1944, to May 20, 1952.The show followed the adventures of Ken Thurston, also known as "Mr. X," an American intelligence agent (later described as an international troubleshooter). Thurston traveled the globe to address threats to peace, U.S. security, and the world. He often found himself in exotic and dangerous locations, dealing with mystery, intrigue, and romance.The lead role of Ken Thurston was played by the British actor Herbert Marshall. He was joined by his comedic sidekick, Pegon Zellschmidt, a somewhat shady character who would inevitably show up in remote parts of the world, often claiming to have a "cousin" there. Pegon, despite his questionable past, would both annoy and assist Mr. X. Leon Belasco played Pegon for most of the show's run, with Hans Conried in the earlier episodes.The series was known for its globe-trotting nature, with Thurston facing various international dangers from spies and criminals to political unrest. The show often began with an announcer setting the scene, emphasizing the mysterious and dangerous places where "The Man Called X" could be found."The Man Called X" was created by Jay Richard Kennedy. It was later adapted into a 39-episode syndicated television series (1956–1957) starring Barry Sullivan as Thurston.