Accompanying an engineer down a mine shaft, a wealthy American discovers a series of caverns in which dwell the subterranean Vril-ya race. Yet not only have the Vril-ya 'people' devised the means with which to survive underground, they have also developed a highly sophisticated language, culture and civilization. Subservient to the mysterious and all-powerful force of Vril, they are primarily a peaceful race; but with a destiny to eradicate human civilization, it can only be a matter of time before they emerge from their underground caves to take on the world as we know it.