“Someone up there is waging war on the Earth.”

Buck Rogers (Buster Crabbe), Dale Arden (Jean Rogers) and Dr. Zarkov (Frank Shannon) have just returned from defeating Emperor Ming on the planet Mongo. They have had little time to rest on their laurels when a mysterious beam of light starts disrupting and destroying the Earth's atmosphere.

Thinking that the disruption is coming from the planet Mongo Buck, Dale and Dr. Zarkov are tasked with returning to the planet to find out what is going on and to stop it. Once they are in flight they find a stowaway in the form of reporter Happy Hapgood (Donald Kerr). Once in space Dr. Zarkov realizes that the light is actually coming from the planet Mars.

Once on Mars the group finds that their old enemy from Mongo, Ming the Merciless (Charles B. Middleton), is actually alive and is in an alliance with Azura (Beatrice Roberts), the Witch Queen of Mars. Ming and Azura are operating a gigantic Nitron ray that is destroying Earth's atmosphere.

Azura has powers that come from a large white sapphire that she wears. She can appear and disappear in a puff of smoke and can change people into figures of living clay. As Clay People that are condemned to live in darkened caves. The Clay People, led by their King (C. Montague Shaw), know the secret of Azura's power but can not escape their dark existence to beat her.

The Clay People capture the Earthlings and order Flash and Zarkov to retrieve Azura’s power gem. They hold Dale as hostage to ensure that Flash does as they ask. Eventually Flash earns the trust of the Clay People. Together they form an alliance to defeat both Azura and Ming.

Flash and his term then venture into the realm of the Forest People hoping to gain their assistance, however, the Forest People are under Ming’s command. The Forest People possess the only weapon that will combat Azura’s power. A black sapphire. Flash must obtain the black sapphire if he ever hopes to defeat Azura and Ming and save the Earth.

“Flash Gordon’s Trip To Mars” was released in 1938 and was directed by Ford Beebe, Robert Hill and Frederick Stephani. It is Universal’s 38th serial and the second of three Flash Gordon serials.

Some of the stock footage used was from the first Flash Gordon movie. In a couple flashback sequences Dale Arden is a blond whereas in this sequel she is a brunette. Normally that could be explained in some way but since the movie is a direct sequel and the beginning of the movie is supposedly their return from the planet Mongo I doubt that she both dyed and cut her hair on the spaceship returning to Earth. The bullet car set came from “Buck Rogers” 1939.

Chapter Titles: 01. New Worlds to Conquer; 02. The Living Dead; 03. Queen of Magic; 04. Ancient Enemies; 05. The Boomerang; 06. Tree-Men of Mars; 07. The Prisoner of Mongo; 08. The Black Sapphire of Kalu; 09. Symbol of Death; 10. Incense of Forgetfulness; 11. Human Bait; 12. Ming the Merciless; 13. The Miracle of Magic; 14. A Beast at Bay; 15. An Eye for an Eye.