A gang of street kids work with the FBI in their attempt to find and rescue their leader's father, a scientist who has been kidnapped by a terrorist group.
A mysterious criminal known as The Whispering Shadow commits crimes by means of a gang he controls by television and radio rays. Jack Norton, whose brother was murdered by The Whispering Shadow, suspects that the eerie Professor Strang - whose ghostly wax museum contains figures far too lifelike - may be involved in the crimes.
When his father is killed in a train wreck, Larry Baker vows to unmask a mysterious criminal called "The Wrecker," who has targeted the L&M Railroad for deadly" accidents."
A 14-episode serial in which Mala, a Polynesian in the employ of U.S. Intelligence investigates sabotage on Clipper Island. A gang of spies causes the eruption of a volcano, for which our hero is blamed. He convinces the local Princess Melani of his innocence and helps her ward off a takeover by rival high priest Porotu.
New York City policewoman Casey Jones' assignment to fight crime often entails her going undercover in some of the seediest and most dangerous parts of the city.
Three government aviators called the "Flying G-Men", one of whom is disguised as "The Black Falcon", fight to protect the US and its allies from an enemy spy ring and to avenge the death of the fourth Flying G-Man.
The Eagle uses sky writing to make threats against a corporation. Nathan Gregory owns a traveling fairground and is thought to be the Eagle. Craig McCoy is a pilot who goes looking for the Eagle when Gregory turns up missing.