Dr. Herbert Lee (John Paul Jones), an archaeologist seeking to decipher ancient Mara inscriptions, is aided by his son, Terry (William Tracy), and Terry's pal, Pat Ryan (Jeff York), and Normandie Drake (Joyce Bryant). Fang (Dick Curtis), a jungle pirate and warlord,plots to kill The Dragon Lady (Sheila Darcy), Queen of the Temple of Mara, and seize the treasures of her ancestors. Both Fang and The Dragon Lady have sworn death for any foreign intruders.

A Secret Service agent searches the jungle for his missing brother, also an agent. He encounters a young woman there who is also searching, but for her missing father. They encounter a gang of ivory smugglers who hold a prisoner who knows the secrets of the missing people and a lost treasure. The pair are also menaced by a giant gorilla which guards the temple which is the smugglers' lair.

The nefarious Dr. Fu Manchu searches for the keys to the tomb of Genghis Khan, in order to fulfill a prophecy that will enable him to conquer the world. His nemesis, Dr. Nayland Smith, and his associates fight to keep the evil doctor from getting his hands on the keys.

Using a diabolical disguise, Harry Crowel embarks on a vengeful career of destruction...opposed by three heroic daredevils.

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.

Deadwood Dick, a masked and mysterious hero, is in reality Dick Stanley, editor of the Dakota Pioneer Press and a leading member of Statehood For Dakota. He is on the trail of a masked villain known as the Skull, who leads a violent, renegade band infamous for its violence against the Deadwood residents' wishes for a statehood status.

A Coast Guard officer is assigned to protect the coastline from spies, saboteurs and enemy agents.

US naval officer Don Winslow is given command of the islands near Pearl Harbor. He discovers that there is a ring of saboteurs and enemy agents who are trying to destroy ships carrying supplies to the troops stationed in the islands and sabotage the war effort. He sets out with his trusted assistant and two beautiful women to find the mastermind behind these nefarious activities.

A mysterious master criminal known as The Voice plots with his gang to sabotage the Milesburg Oil Company, but the rightful heir has a secret army of her own to protect her rights.

A frontier newspaper editor Kirby battles outlaw Tiger Morris who is causing indian uprisings to drive away settlers so that he will can claim a gold deposit as his own. With the help of General Custer, right wins out. Presented in serial form in 12 episodes.

A crime fighter known as The Spider battles a villain called The Octopus, who is out to sabotage America and install his own government.

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.

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.

A masked hero called "The Eagle" leads California ranchers in a struggle against Russian Cossacks who are plotting to take over California and turn it into a Russian colony.

Professor Davidson and his niece Diana Palmer search Africa for the Lost City of Zoloz, reputed to be the source of a large hidden treasure. Also searching is a local crook, Singapore Smith, and Dr. Max Bremmer, who plans to destroy the peace in which the native tribes have been living. However, Godfrey Prescott, otherwise known as the Phantom, is feared and respected by the natives and is able to circumvent the traps and schemes of the villains.