Flash Gordon Conquers the Universe is a 1940 twelve episode serial film starring Buster Crabbe as Flash Gordon, and was the last of three Flash Gordon serials made from 1936 to 1940. The serial was directed by Ford Beebe and Ray Taylor, written by George H. Plympton, Basil Dickey, and Barry Shipman from Alex Raymond's comic strip, and produced by Henry MacRae. The supporting cast features Carol Hughes as Dale Arden, Charles B. Middleton as Ming the Merciless, and Roland Drew as Prince Barin. In 1966 the serial was edited into two feature films for television showing Purple Death from Outer Space and Perils from the Planet Mongo.

A deadly plague is ravaging the Earth, known as the Purple Death because of the spot left on victims' foreheads. Ming the Merciless is suspected to be behind the plague and it is discovered that his spaceships have been dropping "Death Dust" in the Earth's atmosphere. Flash Gordon, along with Dr. Alexis Zarkov and Dale Arden, is sent to the planet Mongo to find a possible cure for the plague. They eventually find an antidote, called polarite in the Kingdom of Frigia. Flash and Zarkov distribute the antidote the same way the original Death Dust was spread. Ming sends an army of robot bombs after the three and he succeeds in capturing Zarkov for a short time before Flash frees him.

The trio continue to battle Ming and his allies. Ming's Captain Torch is the "head villain" of this serial. He is in charge of stopping the Earthlings. Before Flash and his team leaves, they kill Ming by locking him in a tower and crashing a rocket ship loaded with Solarite into it. Prince Barin takes his rightful place as ruler of Mongo. Ming's last words are "I am the universe!". Zarkov announces that Flash Gordon has conquered the universe.

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