The shadow was amateur criminologist Lamont Cranston. He had learned “the hypnotic power to cloud men’s minds so that they cannot see him”. The opening to the show, “Who knows … what evil … lllllurks … in the heart of men? … The Shadow knows! His “friend and companion, the lovely Margo Lane, is the only person who knows to whom the voice of the invisible Shadow belongs”. Together they confront the maddest assortment of lunatics, sadists, ghosts and werewolves ever heard on the air.
Radio broadcasting was the cheapest form of entertainment, and it provided the public with far better entertainment than most people were accustomed to. As a result, its popularity grew rapidly in the late 1920s and early 1930s, and by 1934, 60 percent of the nation's households had radios.