What happens
The Man Called X, a radio mystery series starring Herbert Marshall, opens with a visit from Mrs. Maestas, who asks the Bureau for help after her son, Dr. Maestas, a cancer researcher in Athens, is shot dead and radioactive isotopes meant for his work go missing. Ken Thurston, the man called X, looks into the lost shipments, which were reported lost near the island of Xenophon. His inquiries lead him to a mercantile company, a hospital in Athens, and a sponge-diving operation, with Pagan and several other figures moving through the story. The episode is a 1950 broadcast dated October 27 of that year.
New York City and then Athens, Greece, with the island of Xenophon in the Aegean Sea
Characters: Ken Thurston, Pagan, Mrs. Maestas, Dr. Maestas, Demetrios Sedor, Dr. Eleanor Mitter, Colonel Creighton, Smith
Listen for: The shipments of radioactive isotopes lost near Xenophon and the mysterious murder of Dr. Maestas
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.