The Man Called X is an espionage radio drama that follows the adventures of the suave and sophisticated Ken Thurston, an undercover international troubleshooter for a mysterious American governmental agency. Assisting him is the shady character Pegon Zeldschmidt, played by Leon Belasco. The series, known for its captivating stories featuring danger, intrigue, and romance in exotic settings, was directed by Jack Johnstone, with music credited to Johnny Green. The show's famous tagline was, "Wherever there is mystery, intrigue, romance, in all the strange and mysterious places of the world, there you will find The Man Called X".

The Man Called X first aired from July 10 to August 28, 1944, on CBS, before moving to the Blue Network for roughly six months, from September 9, 1944, to March 3, 1945. It then found its final home at NBC, where it was a summer filler for the Bob Hope Show in 1945 and 1946 before becoming a regular part of the NBC lineup from 1947 until the final radio broadcast on May 20, 1952. The show was sponsored by various companies, most notably Frigidaire and General Motors. The series was later adapted for television in the early 1950s, with Barry Sullivan starring, though it had a short run.

Sources: archive.org, wikipedia.org, otrcat.com