Disaster seems imminent when scientists discover that the planet Mongo is about to crash into Earth. Luckily, heroic young Flash Gordon is on hand to lead an investigative mission into outer space and onto the speedily approaching planet. There, he and his best girl, Dale, who is along for the ride, learn that Ming, the devious ruler of Mongo, has purposely put the planet on a collision course with Earth, and only Flash can stop him.

Jessie, a young working class woman, seeks to improve her life by marrying her boyfriend, only to find out that he is no better than what she left behind.

In this western, a Spanish-American war veteran cannot find gainful employment. In desperation, he becomes a cattle rustler until he can get back on his feet. Just as he is ready to go straight, his girlfriend's younger brother is shot.

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.

Two down-on-their-luck former outlaws volunteer to be Texas Rangers and find themselves assigned to bring in an old friend, now a notorious outlaw.

After healing the leg of the murderer John Wilkes Booth, responsible for the assassination of President Abraham Lincoln, perpetrated on April 14, 1865, during a performance at Ford's Theatre in Washington; Dr. Samuel A. Mudd, considered part of the atrocious conspiracy, is sentenced to life imprisonment and sent to the sinister Shark Island Prison.

Two expeditions are trying to reach the Lost City of Zoloz -- one headed by Professor Davidson, a scientist who wants to establish an archaeological site, and the other by a greedy treasure hunter who wants to keep the fabled treasures of the city for himself. An agent of a foreign power also wants to establish a secret airbase there, so he stirs up the natives against The Phantom, who has been able to get them to stay peaceful so far. When The Phantom is murdered, his son takes his place and sets out to restore peace to the jungle and stop the agents' and the treasure hunters' nefarious plans.

A playwright has his career ruined when he is drunk on the first night. His wife dies having left him, and when his daughter triumphs in the revival of the play he dies contented.

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.

Edited version of the 1940 Universal serial "Flash Gordon Conquers the Universe", released in a syndication package to TV in 1966.