A young girl journeys to Africa to find her father, an explorer who vanished in the jungle.

From his secret laboratory, Captain Z-Ro and his associates use their time machine, the ZX-99, to learn from the past and plan for the future.

Prof. Millard pretends to be dead and helps Jeff King ferret out Vulcan, the evil traitor at the science academy. Donning his Rocket Man costume King goes from one hair raising rescue to the next in order to keep the newly invented Decimator out of the clutches of Vulcan and his minions.

Young Pauline is left a lot of money when her wealthy uncle dies. However, her uncle's secretary has been named as her guardian until she marries, at which time she will officially take possession of her inheritance. Meanwhile, her "guardian" and his confederates constantly come up with schemes to get rid of Pauline so that he can get his hands on the money himself.

Nat Cutler, known as Hawkeye, is a fur trader. With his faithful Indian companion Chingachgook, the last of the Mohican tribe, he fights to protect settlers against the raiding Huron Indians.

When some men are attacked by Indians, a survivor obtains an Indian medicine arrow. An Indian tells Blade he has found gold but will not tell him where until he has that arrow. So Blade starts killing the survivors of the attack but fails to get the arrow. One of the men he kills is John Cardigan and Kit Cardigan, a Scout for Custer, now starts looking for the killer of his father.

Two investigators for a stagecoach company are assigned to find out why the company's stages keep being ambushed. They discover that the culprits are white men disguised as Indians, and they set out to discover who is behind the plot.

During the latter stages of the Civil War, a gang of supposed Confederates, headed by Alex Morel (Lionel Atwill), raid all gold shipments destined for Washington from Oro Grande, California. In the first chapter, "Murder By Accident", Captain Steve Clark (Dennis Moore), is recognized as a Union Secret Service agent by Morel's accomplice Trina Dessard (Virginia Christine), and, with his friend Idaho Jones (Joe Sawyer), is ambushed in the baggage car and sent to almost certain death when the car is un-coupled and plunges down the mountainside. Leaping to safety, in order to be around for the next 12 chapters, Idaho and Steve report to Colonel Sewell (Addison Richards) in Oro Grande, and Idaho introduces himself as a Wells Fargo detective to Cathy Haines (Wanda McKay), the Oro Grande company agent. Steve and Idaho learn that the Morel raiders are only posing as Confederates, and their headquarters are at Morel's "Golden Eagle" saloon. In a raid on the hideout, Steve's brother Jim (Gene Garrick) is killed by the gang. The next victim is Confederate Army Captain Clay Randolph (Regis Toomey) who has discovered that Morel is connected with a group of Prussian spies and gives Steve a clue before he dies. The clue leads Steve to a San Francisco dive owned by Abel Rackerby (Charles Wagenheim), who, thinking he has Steve in his power, exposes the ring's activities and operation methods. Aided by the San Francisco Secret Service, Steve escapes and returns to Oro Grande, where in Chapter 13, "Golden Vengeance", he and Idaho round up the spies.

An expedition sets off for the last land of Mu, where legend has it that a killer death ray is emitted from the eye of a golden idol.

Beyond Hell's Gate Pass is territory controlled by a man who calls himself King Carter; he uses a variety of schemes to prevent the railroad from being built, for fear it will finish his control of (what he considers) his land.

Cowboys and a businessman compete to find lost treasure.  

A murderous gang of counterfeiters has kidnapped the government's best engraver and is forcing him to print virtually undetectable phony money. The Secret Service sends its toughest agent, Jack Holt, and a female partner after the gang.