Dr. John Meredith has been driven from civilization by the criminal activities of his twin brother Bradley Meredith. With his infant daughter, he settles in the African jungle, where his ability to cure the native ills has resulted in his virtual control of the Masamba tribes, who possess vast diamond mines coveted by a gang of crooks. They use Shamba, a witch doctor jealous of Dr. Meredith's influence over the tribe, to further their schemes. They lure Dr. Meredith away from the jungle, and he is murdered by "Slick" Latimer. The natives believe that a sacred amulet is the secret of Dr. Meredith's power, and Shamba attempts to kill Nyoka, Meredith's now-grown-up daughter, to obtain the amulet (which actually contains the secret to the entrance of the Caves of Nakros). Jack Stanton rescues her and assists her in her efforts to recover the amulet. Latimer works with Shamba, and with Bradley Meredith, who poses as his murdered-brother so successfully that even Nyoka does not realize the deception.

Foster (Charles Miller (IV)', owner of the local stagecoach line in Canyon City in the 1880s, has received a Federal Franchise Commission grant and is rushing to complete a new road through the lawless Comanche Strip with the aid of his daughter, June (Kay Aldridge), and his construction foreman "Red" Kelly (Eddie Acuff). Unbeknownst to them, their supposed friend, land-and-cattle dealer Martin Dexter (Robert Frazer), and the town lawyer, Silas Higby (Ted Adams), have plans of their own; should Foster's road see completion, homesteaders would occupy the strip and ruin Dexter's plans to buy the 500,000 acres for cattle-grazing land. Dester hires a band of renegade Indians to attack the road crew. Indian scout Jim Brady (Budd Buster)sees a supply wagon driver by "Red" and June being cased by the renegades, alerts the work-camp crew and then rides to summon Captain Duke Cameron (Allan Lane) and his U.S. Cavalry troop but, before they arrive, Foster has been killed along with many of his workmen. Cameron, a long-time friend of the Foster family, later requests his commanding officer, Colonel Andrews (Stanley Andrews) for a furlough to aid June in continuing her father's project. He then seeks to find out who is behind the renegade attack and, eleven cliffhangers later does so in the final chapter of this 12-chapter serial.

Dick Tracy goes up against a villain known as The Ghost, who can turn himself invisible.

Wild Bill Tolliver and Missouri Benson ride into the territory of New Mexico to search for Bill's father, Henry Tolliver, who disappeared while prospecting. They discover that a ruthless outlaw leader, Jonathan Kincaid, has joined forces with Carl Engler, a renegade European general, and Kincaid owns a giant gold mine and uses captured Mexican patriots, and others, to work as slaves on his property. Bill and Missouri become friendly with Consuelo Romeros, an agent for the Mexican government, and they learns that Bill's father is among the prisoner/slaves in the mine. After freeing his father, Bill sets out to smash both the slave-mine operation and Engler's attempts to overthrow Benito Juarez, the legal president of Mexico.

Miserly old Anton Benson once recovered a treasure in gold from a sunken Spanish galleon, and in his greed murdered anyone who got in his way of keeping it. Now his family is gathered at his estate, Bensonhurst, and they are all searching for the treasure, which is hidden somewhere on the estate. Also looking for the gold is a masked killer called The Iron Claw, who murders one member of the family and lets the others know that they'll be next.

The chapter-crunched version of this 196 minutes, 12-episode serial from Republic finds Canada being bombed mercilessly by a mysterious-enemy plane (shaped like a boomerang) called the Falcon, under the supervision of Admiral Yamata, Count Baroni and Marshal von Horst, chiefs of the Axis Fifth Column in Canada. No one can identify the plane until American inventor, Professor Marshall Brent, and his daughter Carol arrive with a new type of airplane detector. This poses a threat to the Axis chiefs in preparing western Canada for an invasion and they have him kidnapped by local Quisling Gil Harper. RCMP Sergeant Tom King attempts to rescue Brent, but the inventor is killed when a plane in which he is held captive crashes into a riverboat. Carol, determined to carry on her father's work and with King's aid, manages to prevent the enemy agents from capturing the detector, and destroys the device (many chapters later) when the agents make a last desperate attack on the cabin where it is hidden. She is captured and taken to the crater of a volcano, where the ring makes its headquarters.

A sea captain about to be hanged for a murder he didn't commit is rescued from the gallows by two of his crewmen. They head for the island of Pulinan, where they believe the real murderer--the captain's former partner--is hiding so the captain can clear his name. As it turns out, their troubles are only beginning.

Greedy oil speculators, led by Morgan, are trying to force Tiger Woman and her band of warriors from their jungle home. Allen Saunders of Inter-Ocean Oil wants to develop the oil, too, but fights with Tiger Woman to stop the bad guys.

Reporter Brenda Starr (Joan Woodbury) and her photographer Chuck Allen (Syd Saylor) get involved in a search for the loot from a payroll robbery. Cliffhanging action and adventure and a fair amount of comic relief follow them at every turn.

Government agents battle a gang of Nazis who are trying to use the Orotron machine, which can turn seawater into gold.

The evil and masked "Gargoyle" is sabotaging all of America's industrial plants. It is up to the Spider to save the country.