John Sterling completes the chemical formula which will completely protect him from the underworld's bullets, unlike his murdered father who was killed by a group of ruthless gangsters. John bathes himself in the formula, which has been poured into a cauldron of molten steel......dives in, and emerges as a man with the resistance, the magnetism and the strength of steel.; The Shane twins are rich Americans who join the British Air Force to continue a feud with the German sportsman, Herr Schultz.; Captain Valor resigns his commission in the U.S. Marine Corps to seek adventure, and, aided by Ronnie and Angie, heads to China to battle the evil Ho Tsin.; The king of Ritania begs Zambini to help him win the war against Hundania. Hundanian spies place a huge and deadly cobra, whose bite means death, in Zambini's bedroom.; Jim Kendall has devoted himself to wiping out gangland since the death of his wife and child while flying in a hijacked plane, which crashed, and in which all were killed except Jim. In the accident, his face muscles were paralyzed and Jim became the man who never smiled. Kendall has a giant scientific brain, and uses that science to the aid of his crusade.; The Cattleman's Association has sent Nevada Jones to help Irene Cox prevent her herd being stolen by rustlers.; A young girl's father is missing after a series of weird happenings. She suspects foul play and contacts Dudley for help, who dons a purple costume with yellow cape and ventures out to help as Mr. Satan, international detective and soldier of fortune.