Plans for a sequel to 1939's Buck Rogers were scrapped when the public cried out for Buster Crabbe, who had also played Buck, to resume his "proper" role, and MacRae soon began work on the third and last in the series, Flash Gordon Conquers the Universe, to be released in late winter 1940.
With MacRae back in charge, authenticity was again in the ascendant. In four years the strip had matured into one of the most beautifully drawn features on the comics pages, and this was reflected in the designs of the serial, making it one of the most opulent chapter-plays ever. Each of the main protagonists got several changes of wardrobe, with Dale seeming to get a new outfit every couple of chapters. Ming exchanged his robes for a tailored military uniform, and the Arborians all wore snazzy Merry Men cast-offs.
Writers Plympton and Dickey returned, joined by Barry Shipman. Possibly to avoid mentioning "Trip to Mars", the script contains no direct references to earlier adventures, just a few general remarks. Ray Taylor also came back, to officially co-direct with Ford Beebe. The two teamed much in the same manner as Republic's Bill Witney and Jack English, alternating shooting days.
Standing sets from Green Hell and Tower of London, recently vacated, were pressed into service, and an assortment of movable wall flats were juggled and augmented with lighting effects to provide corridors. The impressive cliffs of Red Rock Canyon, just north of Mojave, and various back-lot areas were used for exteriors. One section of studio hillside was silvered up to match stock footage from the German The White Hell of Pitz Palü (which Universal had released in 1930, with an added sound and music track) for an arduous trek into forbidding Frigia, the polar land on Mongo. Jerome Ash and Eddie Keyes' miniatures rounded out the landscape, as well as the skyscapes with an assortment of new and old rocket ships.
Another lavish element is the sound track, with its variety of ray-gun blasts, explosions, and rocket motors. And the music – beginning with a rousing excerpt from "Les Preludes" by Franz Liszt behind the Main Titles and including newly orchestrated pieces originally heard in features such as Bride of Frankenstein, Son of Frankenstein, and Tower of London – makes the film as delightful to the ears as to the eyes.
A MacRae innovation that had previously seen service in Buck Rogers and other titles was the receding roll-up foreword, in which paragraphs of re-capitulation scroll up the screen and angle away from the viewer toward the upper frame line. George Lucas liked this so much that he later used an animated version for the "Star Wars" series.
To see Chapters 6-10 and read more of How the Serial "Flash Gordon Conquers the Universe" Was Made click here.