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.

Two prospectors, one the father of Skye "Lightning" Bryce and the other the father of Kate Arnold, find a large gold deposit belonging to an Indian tribe. They head for home but each sends a note to their respective off-springs advising them of their good fortune. One of the fathers conceives a plan of taking a dagger and wrapping a piece of string around the blade, after which he prints on the string with a lead pencil, the exact location of their find. If something happens to them, the string goes to the son and the knife to the daughter. That night an Indian approaches their camp and blows some mysterious wolf powder which causes a man to see wolves in place of human beings. Lightning's father see his partner as a wolf and stabs him to death; later he is brought into town in a dying condition but before dying, hands the knife and the string over to the sheriff with instructions to deliver to Lightning and Kate.

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.

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.

Rex, a wild stallion, and Rinty, a police dog, are pals. Their master , John Sheldon, is framed for murder, and Alice Ingram plans to race Rex for money to pay for John's legal defense. Meantime, Frank Nolan, who has falsely accused John, sets out to steal Rex for himself.

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.

An intrepid reporter and his loyal friend battle a bizarre secret society of criminals known as The Vampires.

Superhero Captain America battles the evil forces of the archvillain called The Scarab, who poisons his enemies and steals a secret device capable of destroying buildings by sound vibrations.

The misadventures of a suburban boy, family and friends.

American adventurer Richard Grant is falsely accused of murdering an Indian noble and escapes to Africa in search of diamond field and the real culprit.

Tom King Jr. seeks to discover who murdered his father, a Texas Ranger; the trail leads to a network of Axis spies.

Secret Service Major Steel (Joseph W. Girard), is one of the few men in America aware of the fact that Captain Albright (Dave O'Brien) is also Captain Midnight, daring masked aviator dedicated to fighting gangsters and enemies of America. When murderous bombing attacks are made on West Coast munitions plants, Steel sends for Albright and asks him to track down the mysterious Ivan Shark (James Craven), the foreign agent mastermind behind the attacks. Shark has learned about an ingenious range finder, invented by John Edwards (Bryant Washburn, and makes plans to obtain a model of the invention. Edwards instructs his daughter, Joyce (Dorothy Short), to bring the model to Albright for safekeeping in his mountain laboratory. Shark takes Edwards prisoner by Albright assures Joyce that her father will be saved and an end put to Shark's reign of terror. Dressing as Captain Midnight and enlisting the aid of his friends, Chuck (Sam Edwards) and Ichabod Mudd (Guy Wilkerson), Captain Midnight delivers on his promises fourteen chapters later.

The Canadians have discovered a valuable substance called Compound X, which can cure infantile paralysis. When a country at war with Canada learns that Compound X also contains magnetic properties that could aid them in their warfare against the British, they send agents to infiltrate Canada and steal a large quantity of the substance. It's up to Sgt. King (Allan Lane) and his Mounties to track down the agents and put an end to their scheme.