Ford Beebe	...	(Director)
George H. Plympton, Basil Dickey	...	(Writer)
Buster Crabbe	...	Flash Gordon
Carol Hughes	...	Dale Arden
Charles Middleton	...	Emperor Ming
Anne Gwynne	...	Sonja [Chs. 2, 6-12]
Frank Shannon	...	Dr. Alexis Zarkov
John Hamilton	...	Professor Gordon [Chs. 1, 4]
Herbert Rawlinson	...	Dr. Frohmann [Chs. 1, 4]
Tom Chatterton	...	Professor Arden [Chs. 1, 4]
Shirley Deane	...	Princess Aura
Lee Powell	...	Captain Roka
Roland Drew	...	Prince Barin
Don Rowan	...	Captain Torch
Victor Zimmerman	...	Lieutenant Thong
Edgar Edwards	...	Captain Turan
Ben Taggart	...	General Lupi [Chs. 1-2]

Summary: 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, this time with ready-made allies waiting: Prince Barin of Arboria and Queen Fria of the frozen northern land of Frigia; where, it so happens, is found polarite, antidote to the plague. But Ming will use all his forces to keep our heroes from thwarting his plans of conquest...