When a deadly Nitron ray strikes Earth, Flash Gordon and his friends travel to Mars to battle Ming the Merciless and his new ally Queen Azura.

Sam Bisbee is an inventor whose works (e.g., a keyhole finder for drunks) have brought him only poverty. His daughter is in love with the son of the town snob. Events conspire to ruin his bullet-proof tire just as success seems near. Another of his inventions prohibits him from committing suicide, so Sam decides to go on living.

Mary Brooks' father, who has been studying ancient tribes, falls into the hands of "the people of Zar, god of the Emerald Fingers." Tarzan helps Mary locate her father, rescues everyone from the High Priest of Zar, and takes Mary to his cave.

In Kentucky just after the Civil War, the Hayden-Colby feud leads to Jed Colby being sent to prison for 15 years for murder. The Haydens head for Nevada and when Colby gets out of prison he heads there also seeking revenge. The head of the Hayden family tries to avoid more killing but the inevitable showdown has to occur, complicated by Lynn Hayden and Ellen Colby's plans to marry.

Adam Larey becomes a fugitive from justice when he escapes after being blamed for a crime he did not commit. He wanders into the desert wastelands and joins an outlaw gang who prey on gold prospectors. Years later, he meets his wife and her gold-prospecting father as they have come there seeking their fortune, and not knowing the danger of the treacherous desert wastes, the poisoned-water holes and the outlaw bands of marauders who roam the desert in search of the gold found by others. He comes to their aid and, eventually, manges to clear his name of the false charge against him.

Edited version of the 1939 Universal serial "Buck Rogers." A 20th Century pilot named Buck Rogers and his young friend Buddy Wade awake from 500 years in suspended animation to find that the world has been taken over by the outlaw army of Killer Kane.

A mysterious plague, the Purple Death, ravages the earth. Dr. Zarkov, investigating in his spaceship, finds a ship from planet Mongo seeding the atmosphere with dust. Sure enough, Ming the Merciless is up to his old tricks. So it's back to Mongo for Flash, Dale, and Zarkov.

1937 film by Robert Florey

Buck Rogers and Buddy Wade are in the middle of a trans-polar dirigible flight when they are caught in a blizzard and crash. Buddy then releases a special gas to keep them in suspended animation until a rescue party can arrive. However, an avalanche covers the craft and the two are in suspended animation for 500 years. When they are found, they awake to find out that the world has been taken over by the outlaw army of Killer Kane. Along with Lieutenant Wilma Deering, Buck and Buddy join in the fight to overthrow Kane and with the help of Prince Tallen of Saturn and his forces, they eventually do and Earth is free of Kane's grip.