Flash Gordon Conquers the Universe (1940)

New Thrills...New Marvels, New Wonders New Thrills!...New Marvels, New Wonders

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.