The best Warner Richmond’s science fiction movies

When the ancient continent of Mu sank beneath the ocean, some of its inhabitant survived in caverns beneath the sea. Cowboy singer Gene Autry stumbles upon the civilization, now buried beneath his own Radio Ranch. The Muranians have developed technology and weaponry such as television and ray guns. Their rich supply of radium draws unscrupulous speculators from the surface. The peaceful civilization of the Muranians is corrupted by the greed from above, and it becomes Autry's task to prevent all-out war, ideally without disrupting his regular radio show.

Clyde Beatty, an animal trainer and circus star, leads a search for his missing girlfriend and her father who were on an expedition looking for a lost tropical island. Using a dirigible as his mode of transportation, Beatty and his band head off in search of the missing explorers only to crash their airship on the same island their friends are located. Battling wild animals and a gang of greedy men searching for gold, Beatty and his party must rescue his girlfriend and father all the while trying to escape their jungle island. Feature version of the same-title serial of the same year, with refilmed sequences substantially altering the plot and characters of the original chapterplay.

Re-edited feature version of serial The Phantom Empire (1935). Singer Gene Autry discovers a race of advanced humans living beneath the earth.