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.

In 1865, Captain Mark Smith of the Confederate Army leads a band of deserters to conquer Texas and rule it as a dictator. In one of his first actions, he captures and assumes the identity of Texas' new Finance Commissioner, Colonel Marcus Jeffries, after having the real man murdered. When a contingent of Texas Rangers enters the territory, Snead, one of Smith's men, leads them into an ambush by Smith's "troopers". The Rangers are apparently wiped out, although one injured survivor is left. The survivor, nursed back to health by Tonto, swears to avenge the massacre and defeat "Colonel Jeffries" and his men.

The Black Magic cult of Ubasti, based on the isle of Lemuria, believes that Nadji, a princess of Egypt, is a reincarnation of their long-dead goddess, Ossana, and intend to sacrifice Nadji so that Ossana may be resurrected. Nadji has taken refuge at the California home of Frank Chandler, an American raised in the east and possessed of White Magical powers, who calls himself "Chandu". Vindhyan, high priest of the cult's California outpost, learns of this and ultimately succeeds in placing her in a trance which Chandu cannot easily break, propelling him to move her to safety, choosing the port of Suva in the South Seas. There, aided by his sister Dorothy, nephew Bob and niece Betty, Chandu is able to revive her and deal with Vindhyan, only to have the evil Voice of Ubasti, highest of the high priests, spirit her to Lemuria through the magic Circle of Ola. Chandu, Dorothy, Bob and Betty set out in pursuit but end up shipwrecked on Lemuria itself, with his family also now held for sacrifice while Chandu is plunged into the endless maze of caverns beneath the evil Temple of Ubasti, shrouded from his own powers by the full forces of Black Magic.

When the ancient continent of Mu sank beneath the ocean, some of its inhabitant survived in caverns beneath the sea. Cowboy singer Gene Autry stumbles upon the civilization, now buried beneath his own Radio Ranch. The Muranians have developed technology and weaponry such as television and ray guns. Their rich supply of radium draws unscrupulous speculators from the surface. The peaceful civilization of the Muranians is corrupted by the greed from above, and it becomes Autry's task to prevent all-out war, ideally without disrupting his regular radio show.

Texas Ranger tries to stop takeover of Indian lands.

A wealthy publisher uses a disguise and calls himself the Green Hornet to fight crime in his city.

A 12 episode serial starring Rex, the King of the Wild Horses and Rin-Tin-Tin, Jr. Rex is brought from the island of Sujan, where he is worshiped as a God-Horse, to the U.S. to be trained as a polo pony. He escapes, meets Rinty and with the help of Frank Bradley is returned to Sujan. The natives have been persuaded to turn against their God-Horse, however he is rescued just in time before he is burned as a sacrifice.

After Tarzan's estate is destroyed by Arabs Jane is sold into slavery by a man posing as a friendly scientist. Tarzan develops amnesia after a blow to the head. When he recovers his memory (from a later blow) he defeats the villain, recovers the fabulous jewels of Opar, and rescues Jane.

A newspaper publisher and his Korean servant fight crime as vigilantes who pose as a notorious masked gangster and his aide.

Corporal Larry Grant and Sergeant "Mac" McGowan, of the United States Marine Corps, are rival for the love of Frances Schiller, but team up to hunt down "The Tiger Shark," a mad, scientific wizard who is holding Sergeant William Schiller, Frances' brother, a prisoner on a wild, jungle island in the Pacific.

Hank Davis, foreman on a huge dam project, enlists the aid of his two flyer friends when a sinister figure known as The Black Ace leads his Mystery Squadron of masked pilots in an attempt to destroy the dam.

Just before World War II, the Chinese and American governments mount a joint operation to prevent the Germans and Japanese from taking over the strategic island of Mandon.

The period is the 1820's and the first wagon train leaves Independence heading west to Santa Fe. In order to maintain his power, the ruthless Official at Santa Fe must not let them arrive and he sends out his men to stop them. The wagon train then has to endure repeated attacks but is aided by a mysterious rider that shoots singing arrows and rides a painted stallion.

An adventurer goes after Nazi spies who have a new death ray called the Paratron.

Tom Wayne rescues Clancy, Renard and Schmidt in the Arabian desert and they join him in going after El Shaitan, a bad guy who is never seen as he tries to wipe out the Foreign Legion.

A military intelligence officer and a pretty reporter try to find a scientist whose inventions can destroy the world.

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.

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."

Tarzan, who has returned to Africa after living in England, sets off to Guatemala in search of an old friend who may have survived a plane crash there. Also in Guatemala are Ula Vale and Major Martling who are out to find the riches of the Green Goddess. They join forces after they learn that a competitor, Raglan, has already set out ahead of them. Tarzan has to rescue everyone after they are taken prisoner. When they get to the hidden city, Tarzan finds his friend alive and the fabulous treasure.

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.

Crash Corrigan, a recent graduate of Annapolis, and Diana, a go-getting reporter, join Professor Norton for a search for the source of a string of earthquakes, Atlantis. They ride Prof. Norton's rocket submarine searching the sea and little Billy Norton, the professor's son stows away, of course. When they find Atlantis they are caught in a war between peaceful Atlanteans, note their white capes, and war-monging Atlanteans, note their black capes. After many harrowing moments for Crash, Diana, Prof. Norton and Billy, they barely get away with their lives when they escape a tower of Atlantis raised to the surface for the sole purpose of dominating or destroying the Earth (Which one depends on the compliance of the upper world dwellers.)

A scientist discovers a formula for making synthetic gold.

Natty Bumppo, known as Hawk-Eye, is a frontiersman in the American wilderness. Together with his Indian friends Chingachgook and Uncas, he fights battles against nefarious white soldiers as well as the vicious Indian Magua and his cohorts.

An evil scientist plots to take over the world from his base in Africa, where he has invented a machine that can cause earthquakes.

Police detectives battle the League of Murdered Men, a gang of resurrected dead criminals.

An evil scientist known as "Mr. M." uses a drug he has developed called "hypnotreme" to help steal submarine equipment. Federal agent Grant Farrell is dispatched to find the mysterious villain and stop his nefarious plans.