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

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

When Decker's gang holds up a stage, henchman Lefty takes a lady's rings. Later lefty accidentally exposes the rings buying ammunition and Cheyenne sees them. When Lefty tries to shoot Cheyenne he is captured. Now Cheyenne wants the rest of the gang and their leader.

Chandu consults his crystal ball and sees that Nadji, Princess of Egypt, is in danger. She is about to be sacrificed by the black magic cult of Ubasti. Headed for the magic island of Lemuria, he is shipwrecked , washed ashore and captured. He becomes invisible, escapes and after numerous detours is able to rescue the princess.

Pulp hero "The Spider" seeks to destroy all criminals. In this serialized adventure, he battles The Octopus, who intends to replace the government of the United States.

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.