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.

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.

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."

The struggle over the Bellamy estate ends with Michael Bellamy accused of murder and killed on the way to prison, while his brother, Abel Bellamy, takes control of the estate for his own nefarious plans.

A gambling ring run out of the Mogul Taxi company is intent on fixing college football games. Football star Harold "Red" Grange is a target for the gamblers, whose thugs try to eliminate Grange from playing. Grange's buddy Buddy is himself vulnerable to blackmail, since he has broken team rules by marrying. The crooks use all their wiles to keep Grange and Buddy from leading their team to victory.

A scientist discovers a formula for making synthetic gold.

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.